Radiology Masters

What are the sections of the colon?

1. Ascending -The ascending colon and right colic flexure are usually to the right of midline. 2. Transverse -The transverse colon passes from right to left, cranial to the root of the mesentery. 3. Descending -The left colic flexure and proximal descending colon are usually to the left of midline. The distal descending colon courses to the midline and enters the pelvic canal to become the rectum.

List 6 things that CT is excellent for

1. IVDD 2. Nasal disease 3. Body cavity masses 4. Elbow dysplasia 5. Portal vein anomalies 6. Radiation therapy planning

Disease Resulting in Bowel Dilation Define Ileus and causes

Failure of intestinal contents to pass through the intestinal tract is termed ileus. This can be 1. Mechanical (e.g. obstructive) 2. Functional (e.g. paralytic) -this is when peristaltic contractions of the bowel stop because of vascular or neuromuscular abnormalities.

What is megaoesophagus?

Functional dilation and hypomotility of the oesophagus -due to neuromuscular dysfunciton -often idiopathic -Can be focal or generalized It is the most common cause of regurgitation in dogs

Error views Whats wrong with the first two?

They are oblique

Is it planterodorsal or dorsoplantar?

You can do either She does the view in the middle most commonly

The normal small intestinal wall consists of alternating hyperechoic and hypoechoic layers List these

hypoechoic mucosa hyperechoic submucosa hypoechoic muscularis hyperechoic serosa M's are hypo

RENAL DISEASES Abnormal Renal Size Give ddx for a large kidney

Renomegaly

=o

the spoon has revealed all this plicated bowel so had hair ties + a linear FB

DDX for a bronchial pattern A big mistake is to just say asthma

1. Allergic -allergy -secondary to lungworm (aelurostrongylus)/heartworm 2. Infection -bacterial -protozoal 3. Irritation -smoke 4.Cancer (uncommon) Can result in a bronchoalveolar pattern 5. Pulmonary oedema -every once in awhile cardiogenic pulmonary oedema can appear like this e.g. DCM dogs can do this

Safety with MRI

1. Attracts metal! -the magnets are never turned off -oxygen bottles! 2.

DJD What are the most commonly affected joints?

1. Hips -The incidence of hip dysplasia varies from breed to breed and exceeds 50% in many large breeds. 2. Shoulder 3. Stifle OA DJD can be idiopathic/ageing related vs secondary Conditions that predispose include -valgus/varus, patella luxation, hip/elbow dysplasia, trauma, joint instability

What is hepatic nodular hyperplasia?

A common benign lesion in older dogs -Usually does not cause any clinical signs but may result in liver value elevations (especially ALP) -t has a variety of sonographic appearances and cannot be differentiated from neoplasia without biopsy. Hyperechoic, hypoechoic, isoechoic, and mixed echogenicity nodules, some with cavitation, are all possible.

What is the meniscus sign?

A curved gas/soft tissue interface in the large bowel can sometimes be seen in an intussusception

What is the roentgen sign approach?

A method for describing radiographic abnormalities 1. Size 2. Shape 3. Location 4. Number 5. Margination 6. Opacity Any radiographic abnormality can be described using one or more of these terms. Remember it is rare to get a definitive DDX from radiographs Rare exceptions are purely morphologic derangements such as fracture, gastric volvulus, or diaphragmatic hernia.

For the humeral head..how can we increase sensitivity of detecting lesions of OCD? *especially in dogs we really suspect it in

A neutral and pronated view As the lesion can be either caudal or caudomedial

What is the arrow pointing to?

A normal opacity! This is the caudal circumflex humeral artery We know this from anatomy but also because its soft tissue opacity Joint mice we can see will always be bone opacity

L5 ratio in dogs - *remember just a guideline)

A ratio less than 1.4-1.6 usually rules out mechanical obstruction Ratios of 1.95 were associated with a 77%-80% probability of obstruction and a ratio of 2.07 was associated with an 86%-90% probability of obstruction

Urogenital

-Describe the normal shape, position and size of the kidneys, prostate gland, uterus and urinary bladder -Recognise common abnormalities of the urogenital tract -Describe how to perform contrast studies of the kidneys, ureters, urinary bladder, and urethra -Describe the risks of these contrast studies -Recognise abnormalities in a contrast study

U/S of the urethra

-Generally limited to the most cranial portion of the pelvic urethra -Having a fuller bladder helps -The layers of the urethra usually cannot be resolved, and the normal lumen is not distended

Hepatic abscess

Abscesses may be secondary to necrotic tumors, ascending portal infection, adjacent infection (pancreatitis), or penetrating wounds

Hiatal Hernias What is this? Types?

Common (suprisingly) Due to a defect in the esophageal hiatus, abdominal organs slide cranially A sliding hernia AKA type 1 hiatal hernia results in cranial displacement of the stomach with the esophagus *more common in cats or dogs A type 2 hiatus hernia is when there is cranial displacement of part of the stomach which is LATERAL to the esophagus. In patients with hiatal hernia, a cranial position of the stomach might be noted radiographically. Additionally a soft tissue mass effect might be present in the caudodorsal thorax

Cryptorchidism When should the testes really be descended by?

Common condition. incidence reported between 1% and 15%. Testes typically should descend into the scrotum by 10 days, and if not descended by 8 weeks of age the patient is considered cryptorchid. Intraabdominal testicles may be located anywhere from caudal to the kidneys to lateral to the urinary bladder trigone.47 Testes in the inguinal superficial soft tissues may be located from an area cranial to the pubis to nearly the perineal region.

Spondylosis Deformans

Common in dogs tends to be most prevalent in the thoracolumbar region and the lumbosacrum Clinicians should be aware that spondylosis deformans is not an inflammatory process but rather a disease of the attachments of the vertebral joints, which involves the fibers joining the intervertebral discs to the vertebral endplate The exact cause of spondylosis deformans is unknown, but etiopathogenesis might include repetitive trauma, instability, normal aging and wear and tear, and hereditary predisposition. Most clinicians and radiologists agree that spondylosis deformans is insignificant, unless a concurrent prolapsed disc is present, or if there is bony impingement on the spinal cord or spinal nerve roots. Nerve root compression from spondylosis is rare except in lumbosacral instability where foraminal impingement results from dorsal extension of the enthesophytes.

EXP

Common primary neoplasms of the small intestine include adenocarcinoma, lymphosarcoma, mastocytoma, gastrointestinal stromal (GIST), leiomyoma, and leiomyosarcoma. In 150 dogs, loss of wall layering was the most predictive feature for differentiating between enteritis and neoplasia.

INtervertebral disc disease Target locations Radiographic signs

Common sites of disc prolapse are C2-C3, C3-C4, T12-T13, and T13-L1. Although clinical signs of intervertebral disc disease are uncommon in cats, cervical disc degeneration frequently occurs in cats older than 6 years old. Radiographic signs consistent with intervertebral disc protru- sion include (1) narrowing of the intervertebral disc space (2) narrowing of the intervertebral articular process joint space, (3) a small intervertebral foramen (4) increased opacity within the intervertebral foramen (5) mineralized disc material within the vertebral canal Remember in normal animals disc spaces at T10-T11 and L5-L6 are usually narrower than adjacent disc spaces. Discal mineralization, so-called mineralization in situ, is indicative of intervertebral disc degeneration but does not confirm that this particular disc is causing a clinical problem. Most prolapsed disc material is non-mineralized or lacks sufficient mineral content to be detected on survey radiographs.

What about on U/S for gastric neoplasia?

Common ultrasound features include 1. thickening of the stomach wall 2. distortion of the normal layered appearance of the wall 3. altered echogenicity and motility in the affected area Similar changes have been reported in cats with eosinophilic gastritis and gastritis secondary to actinomycosis. Wall layering is usually preserved in gastric polyps but may have the appearance of a large sessile mass with the loss of wall layering

Intraluminal changes

Consideration of the gravitational alignment is especially helpful in differentiating calculi and blood clots that gravitate dependently from gas bubbles that rise. *The location of cellular and crystalline debris and fresh hemorrhage is more variable.* Severe acute hemorrhage can fill the urinary bladder and give rise to a lacy hyperechoic pattern, which may change little with ballottement or animal repositioning Lipiduria can be identified as clumped echoes that are suspended within the urinary bladder

What is the difference between constipation, obstipation and megacolon?

Constipation is clinically defined as infrequent and reversible fecal retention, obstipation as permanent but reversible loss of colonic function, and megacolon as permanent and irreversible colonic distension. Colonic impaction (which is seen in all of the above) is characterized by accumulation of feces that are more radiopaque than normal due to continued water absorption from colon contents,

How big is the normal prostate gland in a dog?

Depends on age, size, neuter status.. From bristol.. The lobes are equal size, have a smooth surface and are firm. In an entire male dog, each lobe is typically about 2-3 cm wide, 2-3 cm high, 1.5- 2.5 cm caudo-cranial, although the size varies depending on breed and age. If a dog is neutered the size of the prostate will be smaller. *another study showed shouldn't really be more then 4cm caudo-cranial (even big dogs) Depth shouldnt be more then 2cm

Radiographic signs of aseptic necrosis of the femoral head

Depends on stage of disease course -Early on may appear normal -As it progresses linear lucencies can be seen in the femoral head -Flattening and irregularity of the femoral head and neck become apparent as the affected bone remodels and collapses on itself. This may then lead to subluxation Fragmentation of the femoral head may eventually occur from pathologic fracture. Muscle atrophy and radiographic findings associated with degenerative joint disease usually develop. Radiographic evaluation of both hips is indicated, because this disease may be bilateral.

Radiographic signs Oesophageal disease

Increased radiopacity of mediastinum -Opaque foreign body -Retention of ingesta -Esophageal mass -Mediastinal fluid or mass (secondary to perforation) Increased radiolucency of mediastinum -Esophageal dilation with gas -Pneumomediastinum (secondary to perforation) -Pneumothorax (secondary to perforation) Ventral displacement of trachea Tracheal stripe sign Visualization of longus colli muscles Pleural effusion (secondary to perforation) Aspiration pneumonia

If the dog is in for trauma and not hip dysplasia, which view is fine?

Frog leg

Stats for obstructive radiographs

Good screening test One study found when evaluating for mechanical obstruction, radiographs provide a definitive answer 70% of the time -better at ruling in obstruction (then out) He explains it to clients as a good screening test and good for ruling in but can't definitively rule it out. 1/3 of dogs with obstructions won't have obvious findings. rads are cheap compared to U/S

Sprains

Not visaulised directly by radiography Signs can include (1) periarticular soft tissue swelling; (2) avulsion fractures at points of attachment of ligaments, tendons, and capsules to bone (entheses); (3) joint instability or subluxation; and (4) spatial derangement of the osseous components of a joint. Palpation and manipulation of a sprained joint is usually the best diagnostic tool.

Pancreas - Radiography

Not visualised when normal due to silhouetting with other structures *occasionally the left limb is visible in a normal cat that is obese

L view

Note you don't see any pulmonary vessels in this area (silhouetted) Same for the bronchial wall

Random fact..

Pre-ureteral vena cava (or circumcaval ureter) is a common vascular anomaly in cats (prevalence of 22.4%) where the ureter courses dorsal to the caudal vena cava and displaces the vena cava ventrally. This anomaly has been associ- ated with ureteral strictures in people and may predispose cats for urinary tract signs. Unrelated pic of a pyelogram

Primary bone tumours Where do these tend to start? Can they cross the joint?

Metaphyseal A single metaphyseal aggressive bone lesion should be considered a primary bone tumor until proven otherwise. Primary bone tumours can cross joints and invade adjacent bone if they get large enough Osteosarcomas are the most common primary bone tumour of canines.

Sesamoid disease What breed tends to get this?

Rotties This is a syndrome where the metacarpophalangeal sesamoids are fragmented -mainly the second and seventh palmar sesamoid bones Cause questionable Common cause of forelimb lameness in rotties

What should I do if i see a sewing needle on X-rays?

Sharply pointed radiopaque objects in the small bowel, such as a sewing needle, can potentially cause perforation and peritonitis but sewing needles with or without attached thread have passed through the gastrointestinal tract without complication. Clinical monitoring for signs of perforation and daily radiographic monitoring are justified, and if the sharp object has not passed within 3 days, surgical removal is warranted

Bicipital groove view

She finds following the textbook this view can be tricky to get But a cheat way is to just do a DV chest - you get a really good view of the groove (she will collimate so she just gets both shoulders)

Carpus 2 standard views - list

She uses cellotape when the dog in the lateral position to tape down the paw to keep it in a true lateral position***

cecocolic intussusception

Short axis (A) and longitudinal (B) sonograms of the descending colon of a dog with a cecocolic intussusception. In A, note the ring-like juxtaposed wall layers with alternating echogenicity of the external intus- suscipiens (E) and internal intussusceptum (I) (concentric ring sign) as well as the entrapped hyperechoic mesentery between the segments (M). In B the same wall layers have a parallel orientation

B

Shoulder osteochondrosis (A) and osteochondrosis dissecans (B). The lesions are characterized by concave lucencies of the humeral head and variable surrounding sclerosis. In B there is a linear mineralized cartilage flap visible adjacent to the subchondral defect on the caudal humeral head. A change in shape of the subchondral bone due to osteochondrosis can sometimes be inconspicuous on a straight lateral view due to the rounded surface of the humeral head, and several slightly oblique lateral views can be obtained with the limb in varying degrees of internal rotation (pronation). In B there is also roughening of the bicipital groove (arrows) that is likely associated with bicipital tenosynovitis.

Errror

Shoulders are not separated enough

When might I see mineralization in the spleen?

Similar to the liver Dystrophic calcification of 1. abscesses 2. hematomas 3. fungal granulomas 4. neoplastic masses.

Is mineralization of the costochondral junctions normal?

Yes -It can be seen in young dogs and cats and is nearly always present in older animals Movement at the costochondral and costosternal joints increases as the costal cartilages stiffen from mineralization. This in turn results in osseous proliferation at the costo- chondral and costosternal joints. The opacities resulting from enlargement of these joints may be confused with lung nodules on DV or VD radiographs. Excessive costochondral or costosternal mineralization may also be confused with aggressive processes, such as infection or neoplasia.

Positioning X-rays

humans tend to have a 1:1 ratio crown:root

Developmental lesions are often...

multifocal or generalized e.g. OCD lesions are often bilaterally symmetrical

What are the two most common causes of oesophageal strictures?

secondary to a f 1. Foreign body or 2. gastroesophageal reflux. Esophageal strictures thought to be related to gastroesophageal reflux during anesthesia are usually located at the caudal portion of the thoracic esophagus, caudal to the base of the heart.

Trick Q - you actually couldnt definitively say from rads He did fast scan and found this..

septic peritonitits

You can see in the L lung field there is also increased opacity and air bronchograms

so we don't need the lobar sign to know its an alveolar pattern

Lung Patterns Lecture mixed with the lung chapter Lung anatomy How many lobes are there?

Six Four lobes on the right (cranial, middle, caudal, and accessory) Two lobes on the left (cranial and caudal). *The left cranial lobe is split into cranial and caudal segments *There is considerable overlap in X-rays

q2

this shows the importance of a DV and VD for these cases -VD better for heart shape, DV better for pulmonary vessel assessment

Spondylitis

Spondylitis is a nonspecific term referring to inflammation of the vertebrae. Common causes of spondylitis include microbial infection, plant awn migration, and infection with Spirocerca lupi. Paraspinal abscesses may extend to the spine and cause spondylitis. Radiographic changes are mainly those of -increased opacity of the vertebral body with a periosteal reaction. With osteomyelitis, radiographic features include an aggressive bone response with patchy lysis of the vertebral bodies and an irregular periosteal response

Subungual tumours vs subungual infections How can I tell these apart on X-rays?

You cant. The digit is also a location where radiographic differentiation between infectious and neoplastic bone lesions is impossible The most common canine subungual tumor is squamous cell carcinoma, commonly occurring in large-breed dogs with black hair coats. Melanomas are another common canine subungual tumor. Inflammatory conditions of the digit are also common. Digital tumors typically involve a single digit; however, a syndrome of metastasis of pulmonary tumors to multiple digits has been identified in cats

still werent totally convinced so repeat rads taken

can see an opacity again in the pylorus (more dorsal this time) - scoped out a large piece of nylabone

Ratio of SI to L5

cats are all similar size so just remember 12mm if <12mm not dilated, if >12mm dilated Can be due to FUNCTIONAL or MECHANICAL ileus

Small kidneys List 3 ddx

-Congenital renal hypoplasia or dysplasia - Amyloidosis -Chronic renal failure *Typically, cortical infarctions are present in chronic renal disease, leading to an irregular cortical margin

Large Intestine What imaging tends to be preferred?

-Endoscopy (samples can also be taken). This has largely replaced contrast radiography of the bowel -U/S can also be used to assess the near wall (faeces/gas often limits visualisation of the far wall), lymph nodes -CT is also great (especially for the pelvic canal)

Renal disease can be difficult to detect radiographically. What changes might we see with renal hyperparathyroidism?

1. Generalized osteopenia -evidenced by thinning of the bone cortex with a double corti- cal line. -The skull is usually affected first 2. Metastatic mineralization of stomach wall, blood vessels, and parenchymal organs (such as, liver and spleen) -this happens if the ca to phos ratio is increased

Decreased hepatic echogenicity may be seen with.. (try and list 3)

1. Hepatic congestion 2. Lymphosarcoma and leukemia 3. Amyloidosis 4. Cholangiohepatitis

Gastrography What is this? What are the types?

Contrast studies of the stomach 1. Pneumogastrography -this is a negative contrast study 2. Positive Contrast Gastrography -e.g. barium -After administration of barium, gastric emptying should start within 15 minutes in most normal patients. -During gastrography with barium sulfate, the stomach generally empties within 1 to 4 hours in dogs -Gastric emptying times for dogs and cats can vary from 4 hours for high-moisture food to 16 hours for dry food. Rapid emptying of the stomach has no clinical significance, whereas delayed emptying is potentially of much greater significance.

This is an example of..

Summation

Can see gas in the pylorus and proximal duodenum - all looks good

Not obstructed v+ due to doxy (he says if you take this as a human you know its not good - the doxy!!) You can still see hairpin loops and stacking though - whats that about? You only apply the rule about hairpin loops and stacking to loops that are GREATER then 1.6 (so you can't call this stacking and hairpin turns)

Osteochondrosis of the elbow

Not related to incongruency -unless its a kissing lesion Affects the medial humeral condyle

Can intestinal wall thickness be assessed on X-rays?

Not reliably but sometimes

Neutral view

Just let the elbow lie at the angle it naturally wants to

Mandibular and maxillary tumours

Tumors of the oral cavity account for approximately 6% to 7% of all canine cancers and 3% of feline cancers -SCC -

Again but with barium you can see the twist

colon torsion showing the twist in the descending colon

How is CT performed?

X-ray that rotates around the patient X-ray detectors are on the other side

Obstructed or not?

You can see some foreign material in the fundus But on VD pylorus/duodenum looks normal

How to improve accuracy for suspected talus ocd lesions?

oblique views! One can see the soft tissue swelling in the first view Red arrow = medial trochlea

Large subchondral defects are frequently associated with the presence of...

separate osteochondral fragments -this tends to increase the severity of clinical signs.

Approximately how big does a nodule have to be before we can see it on X-rays?

~7-9mm

another case of overexposure

someone interpreted this as lysis of the frontal bone from a tumour - but see areas of the nasal turbinates are also absent along with areas of the mandibular cortex so exposure factors were extremely high so theres saturation of the plate and image dropout

Adrenal Glands - Anatomy

-Distinct cortex and medulla _Cortex secretes steroid hormones including cortisol, aldosterone, androgens and estrogens -Medulla produces catecholamine -Both are in the retroperitoneal space -The aorta is medial to the left adrenal gland -The caudal vena cava is medial to the right adrenal gland Not seen radiographically unless enlarged or mineralized -In cats, mineralization of the adrenal glands can occur normally and is generally dystrophic in nature and rarely due to adrenalitis

Principles of Abdominal X-rays

-Obtaining only one lateral and a VD radiograph of the abdomen will not be adequate in many patients as this fails to take advantage of bowel gas serving as a valuable inherent contrast medium. -Take the left lateral view first of the abdomen. The presence of duodenal gas as a contrast medium is more likely when dogs are first placed in left lateral recumbency for the radiographic series. -VD is much preferred over DV In DV the abdomen will be more crowded, organ conspicuity will be reduced, and portions of the pelvic limbs are often superimposed on the abdomen -. The field of view for an abdominal X-ray should extend from just cranial to the diaphragm to the level of the anus/perineum -For lateral views, the pelvic limbs should not be pulled caudally but should be kept perpendicular to the spine. This relaxes the caudoventral aspect of the abdominal wall and reduces crowding. In the VD view, the pelvic limbs should be flexed into a so-called frog-leg position rather than being pulled caudally. If the pelvic limbs are pulled caudally for the VD view, crowding will be increased, and skin folds will be created in the lateral thigh and/or caudal abdomen region

Ancillary factors "female servant.." 1. Body fat 2. Cutaneous lesions

1. Body fat -fat is more radiolucent than soft tissue and provides contrast between organs -In emaciated or young animals there is reduced serosal detail (more difficult to see serosal margins) -Cats often have a particularly large collection of fat in the falciform ligament . This is often misinterpreted as peritoneal fluid. (we know this is not the case due to the principles of radiographic opacities and the silhouette sign. It cannot be fluid, or the absolute opacity of the region would be greater, and there would also be border effacement of the adjacent liver and jejunum.) -Cats also often accumulate large amounts of fat in the omentum and mesentery. This will cause crowding of the jejunum in the midabdomen. Jejunal crowding has been listed as one radiographic sign of linear foreign body. With a linear foreign body, the crowding is caused by plication, and there will almost always be other signs of linear foreign body obstruction, such as eccentric gas bubbles or foreign material anchored in the pyloric antrum. Jejunal centralization as the only sign of linear foreign body is unreliable, but nevertheless the centralization from crowding caused by omental fat is sometimes misinterpreted as a sign of a linear foreign object. 2. Cutaneous lesions -e.g. superimposition of the prepuce and os penis on the caudal aspect of the abdomen in VD radiographs of male dog

A decrease in size of the adrenal gland suggests addisons disease What are other radiographic findings we might see with addisons?

1. Decreased size of the heart, 2. Decreased peripheral pulmonary arteries and caudal vena cava 3. Decreased liver size

Abnormalities of Abdominal Lymph Nodes What are the two things that let us see lymph nodes on X-rays?

1. Enlargement -Of the parietal lymph nodes, the medial iliac nodes are usually the only lymph nodes (don't mistake for vessels!) -Enlarged lymph nodes frequently displace the descending colon and rectum ventrally -Neoplasia is the most common cause for enlargement - can be primary e.g. lymphsarcoma or metastatic e.g. from caudal abdominal or pelvic neoplasms Inflammatory diseases are less common Neoplastic lymph node involvement may be primary (e.g., lymphosarcoma) or metastatic (e.g., from caudal abdominal or pelvic neoplasms).50,51 Inflam- matory disease may also cause enlargement of the medial iliac lymph nodes, but this is less common. 2. Mineralization

Adrenal gland dysfunction usually causes radiographically detectable changes. In patients with Cushing syndrome this may include.. (try for 5)

1. Hepatomegaly 2. Bronchopulmonary mineralization 3. Dystrophic mineralization of the skin and other soft tissues 4. Adrenal gland enlargement with mineralization when functional tumors are present *Pulmonary arterial thrombosis also occurs in dogs with Cushing syndrome, but this is difficult to detect radiographically*

Why are we hesitant to sample adrenal masses?

1. If the mass is a pheochromocytoma, the possibility exists of stimulating a hypertensive crisis from a massive release of catecholamines 2. Adrenal gland tumors have also been reported to hemorrhage spontaneousl

Follow up on image interpretation RADIOGRAPHIC GEOMETRY AND THINKING IN THREE DIMENSIONS A major limitation of radiographic imaging is that the images are two-dimensional although the patient is three-dimensional. Consequences of radiographs being two-dimensional are (1) magnification and distortion (2) image of a familiar part appearing unfamiliar (3) loss of volumetric perception (4) superimposition.

1. Magnification and distortion -Magnification refers to the enlargement of a structure in the image relative to its actual size. -Magnification depends mainly on the distance between the structure and the receiver and as this distance increases, magnification increases. -The effect of magnification is minimized as long as patients are positioned in a standard manner for radiography because any magnification that occurs just becomes part of the normal radiographic appearance. Distortion is unequal magnification that occurs when the object and receiver planes are not parallel. -Distortion leads to the image not being an accurate representation of the true shape or position of the object. Just as with magnification, some distortion occurs in every radiograph because there are always some parts of the patient that are not parallel to the plane of the receiver. Distortion caused by deranged anatomy or nonstandard patient positioning, however, can limit the diagnostic quality of the radiograph 2. Unfamiliar image -Should patient positioning deviate from the standard, the unfamiliarity of the image can result in a missed lesion or an incorrect diagnosis (doesn't fit with pictures in your mental database) 3. Loss of volumetric perception -To evaluate geometry accurately, two radiographs of the object are necessary, with one acquired at a 90-degree angle to the other. So we need a minimum of two views (orthogonal views) 4. Superimposition -Present in every radiograph. Once we view enough we see this frequently recognise most of this as "normal" -The opacity of many superimposition opacities can seem out of proportion (and more opaque) to the actual size of the structure e.g. nipple of prepuce. This is because they are surrounded by air and their margins are parallel to the central X-ray beam -Atypical radiographic positioning can also lead to superimposition -The summation sign is a unique case of superimposition where an opacity is created that does not represent a structure that is actually present within the patient. -Summation can be radiolucent aka "negative" (example of the swiss cheese block being radiographed - the empty regions superimposing would lead to radiolucent shadows -Alternatively it can be radiopaque or "positive" e.g. kidneys overlapping in a lateral -Another common positive summation shadow results from a pulmonary vessel overlapping with a rib. 5. Border Effacement (Silhouette Sign) -occurs when two structures of the same radiopacity are in contact, leading to the inability to distinguish their margin. -Conversely, if two structures of the same radiopacity are separated by a substance of a differing radiopacity, their borders can be distinguished radiographically because of the contrast provided by the intervening substance. Examples -pulmonary vessels superimposed on the heart are commonly misinterpreted in lateral radiographs as a coronary artery rather than correctly as a pulmonary artery (the coronary artery is effaced by the heart as no intervening tissue of a different radiographic opacity is present between them) Disease -border effacement of the R cardiac silhouette in patients with R middle lobe pneumonia -Pleural effusion (especially in DV cases where the fluid pools around the heart) -Peritoneal fluid for abdominal organs

DISEASE OF THE PANCREAS What changes would I expect to see with pancreaitits? (where on the X-ray) - try and list 5

1. Pancreatitis -Acute pancreatitis is a common cause of localized peritonitis Possible radiographic signs 1. Increased soft tissue opacity, cranial right abdomen 2. Soft tissue mass effect caudal to stomach 3. Focal decrease in serosal detail, cranial right abdomen 4. Gas-distended descending duodenum (sentinel loop sign) -Bowel loops adjacent to the pancreas (such as, the proximal descending duodenum) may contain gas; they may also have loss of tone and be dilated. This gas dilation of the duodenum has been referred to as the sentinel loop sign, but this finding is not definitive evidence for pancreatitis. 5. Displacement of adjacent intestinal structures -The proximal descending duodenum may be displaced ventrally or toward the right to produce a broad curvature, and the pylorus of the stomach may be displaced toward the left. 6. Foci of mineralization may occur in areas of fat necrosis **Radiographs may be normal** -On VD the cranial R abdomen is usually more radiopaque then the L even in a NORMAL patient - this is commonly mistaken for pancreaitits

Abdominal Lymph Nodes Anatomy These are divided into two groups which are?

1. Parietal -includes the lymph centers of the abdominal and pelvic walls including lumbar, iliosacral and iliofemoral lymph centres -All except the iliofemoral lymph nodes are in the retroperitoneal space. They recieve lymphatics from the spine, adrenal glands, kidneys, genital organs, caudodosral abdomen, pelvis and pelvic limbs -only ~10% of dogs have an iliofemoral lymph node (its deep in the femoral traingle) -Many of the parietal lymph nodes are developed inconsistently and may be absent. However, the medial iliac lymph nodes ( the largest lymph nodes of the iliosacral lymph center) are constant. -The medial iliac lymph nodes are located ventral to the vertebra (l5-l7) and between the deep circumflex iliac and external iliac arteries. One (or sometimes two) lymph nodes are present on each side 2. Visceral -Have subgroups associated with specific organs -Drains the liver, spleen, pancreas, stomach, and intestine Normal lymph nodes are usually not visible radiographically.

Peritoneal Gas (Pneumoperitoneum) What are the two most common causes of this in small animals?

1. Penetrating injury to the abdominal wall -including laparotomy 2. Disruption of the wall of a hollow viscus (e.g. GIT tract) -not ALL intestinal perforations lead to free peritoneal gas After laparotomy, a moderate amount of gas may persist for days to weeks. In patients with a penetrating wound, differentiating whether free peritoneal gas is caused solely by penetration of the abdomen or is the result of concurrent organ rupture is impossible from radiographs. However, if the penetrating wound is very small and large amounts of free peritoneal gas are present, a perforation of a hollow organ secondary to injury should be highly suspected. If subcutaneous emphysema is superimposed over the abdominal cavity (such as, caused by trauma), it may be difficult to discern whether there is concurrent peritoneal gas or not. Free peritoneal gas usually floats to the highest point within the abdomen. In lateral recumbency, this is usually under the caudal aspect of the ribs or in the mid abdomen. Ultrasound is not commonly used to detect pneumoperitoneum Retroperitoneal gas is uncommon. May be caused by a migrating FB, trauma or surgical access to retroperitoneal space e.g. spinal surgery Can also be caused by perforation of the rectum or vagina or as an extension of pneumomediastinum.

Once these things are considered, then have an standardised approach to interpretation A suggested order is... 10 things

1. ribs, vertebrae, and the visible portions of the pelvis and pelvic limbs 2. soft tissues of the abdominal wall 3. serosal contrast and character of retroperitoneal space 4. contrast and character of peritoneal space 5. parenchymal organs (liver, spleen, kidneys) 6. urinary bladder 7. organs not typically seen 8. stomach 9. duodenum and jejunum 10. the cecum and colon If the same procedure is followed for every patient, the order of searching will become second nature Checklist?

Radiographic technique in the abdomen What type of KV and Ma do we want?

A low kVp/high mAs technique is best This is because the abdomen has inherently low contrast (the difference in radiographic opacity between fat and water (soft tissue) is slight) The above factors will lead to a short scale of contrast, with few gray shades and more blacks and whites. . For patients thicker than 10 cm, a grid should be used to remove scattered x-rays from the beam. Ideally the abdominal X-ray should be taken at peak exhalation. The diaphragm will be further cranial and there is less crowding in the abdomen

Instructions on finding the left adrenal gland on U/S What should it look like?

A peanut! To find the left adrenal gland, the cranial pole of the left kidney is scanned in a sagittal plane, and then the transducer is slid medially to the aorta. The left adrenal gland lies just ventrolateral to the aorta between the cranial mesenteric and renal arteries. Occasionally, the left adrenal gland may be located slightly cranial to the celiac and cranial mesenteric arteries.

Right and left lateral and VD views of the abdomen will suffice for almost all canine and feline patients. If the status of the urethra in male dogs is of concern, as for assessment of urethral calculi, what additional view should be taken?

A third lateral view made with the pelvic limbs pulled cranially. This provides an unobstructed view of the ischial arch and os penis, allowing for assessment of urethral calculi without superimposition of the pelvic limbs

Interpretation

Always make sure ancillary factors and adequate views/positioning are checked before assessing for abnormalities (otherwise you will falsely call normal structures abnormalities) 1. Are the radiographic views adequate, and are all of the views needed present? 2. Is the positioning adequate? 3. Is the radiographic technique adequate, or are the images overexposed or underexposed? 4. Were the images acquired with an antiscatter grid? 5. What is the body habitus of the patient, and how is this going to affect the appearance of the images? 6. Are there morphologic aspects of the patient that are going to influence the appearance of the radiographs? These include things such as cutaneous nodules or masses.

The appearance of the stomach changes between R and L laterals. List 3 things that are important to know about this

Anatomically, the gastric fundus is located dorsally and on the left and the pylorus ventrally and on the right 1. When the patient is in right recumbency, the pylorus will usually contain fluid or ingesta; and if there is gas in the stomach, the gas will rise and collect in the body and fundus of the stomach. Alternatively, when the patient is in left recumbency, the fluid will usually gravitate to the fundus, and gas will rise and fill the pylorus. 2. Of particular importance is the knowledge that in right lateral views, especially in dogs, the pylorus can take on the appearance of a mass or foreign object because of the dependent fluid collection 3. Many small intestinal linear foreign objects are anchored in the pylorus. This emphasizes the importance of a left lateral radiograph to increase the chances of gas being in the pyloric antrum to outline the foreign material

BIPS

Barium contained in a gelatin capsule -Made in 1.5mm or 5mm diameter -Reference ranges of normal orocolic transit times have been developed for cats and dogs. It is emphasized that these reference ranges have been developed with concurrent feeding of prescription meals, and adherence to the manufacturer's instructions is important -Does not allow assessment of intestinal mucosa -Used primarily for assessment of gastric outflow obstruction and intestinal obstruction. With a complete obstruction, the BIPS of both diameters will accumulate proximal to the obstruction. - BIPS may be more suited for assessment for partial obstructive processes where, in theory, the 1.5 mm diameter spheres will be able to pass the obstruction while the larger 5.0 mm spheres will be trapped proximally. -Transient normal bunching of BIPS can occur within the gastrointestinal tract, particularly in the pyloric and ileocolic regions, and sequential radiographs are warranted when there is suspicion of an obstructive pattern when using BIPS. There is one report of aspiration of BIPS

What happens with barium peritonitits? What is the recommended course of action? How can we minimise its formation?

Barium peritonitits - leakage into the abdomen. The presence of barium sulfate complicates bacterial peritonitis by causing progressive exudation of extracellular fluid and albumin resulting in hypovolemia and hypoproteinemia Nodular aggregations on the parietal and visceral peritoneum develop. Fibroplastic proliferation leads to marked fibrinous adhesions. Leakage of barium into other areas such as the mediastinum results in similar changes. Treatment Early aggressive therapy is recommended for barium within the abdominal cavity, including surgical removal of the barium from the abdominal cavity and omentectomy. Minimisation While barium peritonitis is rare, it is difficult to treat and can be life threatening. If a positive contrast study of the gastrointestinal tract is indicated and perforation is of concern, the use of an iodinated water soluble contrast medium is recommended.

Barium Pros and cons (or complications)

Barium sulfate is the standard contrast medium for imaging the gastrointestinal tract. -Liquid most common but BIPS also are available (barium-impregnated polyethylene spheres) Pros -inert (non-toxic) - lack of absorption from the gastrointestinal tract - excellent x-ray attenuation. Complications -Potential leakage into the abdominal cavity (or mediastinum) *abdominal cavity leakage is the most common -Aspiration (small amounts will not cause severe damage but large amounts are of concern) -Retention in the colon with formation of a barolith -intravascular migration/introduction - allergic reactions.

Everyone who interprets radiographs makes errors, regardless of their level of expertise. Two specific errors in interpretation that all interpreters make deserve consideration—these are bias and satisfaction of search. Define these

Bias results from expecting to find something and then making the radiographic signs fit that expectation. For example, in a dog with acute vomiting, a gas-filled jejunum will be more likely to be interpreted as an obstructive pattern than this same pattern in a normal dog. Satisfaction of search pertains to finding an obvious radiographic abnormality and then stopping the search for more lesions, regardless of whether the finding explains the clinical signs. Avoiding these errors is a gradual transition that comes with experience.

Iodine Based contrast media

Can be given IV or directly into a body cavity e.g. iohexol Commonly used in CT imaging to assess vascular anatomy, or leakage patterns from vessels into tissue (increase in opacity is called hyperattenuation in CT) *Iodine does not directly interact with tissue and does not enter cells to any significant degree *Rapidly excreted as long as renal function is normal Adverse reactions -Osmolality (agents are generally hypertonic compared to blood and can lead to intravscular cell damage damage along with vasodilation). -Ionicity -Chemical toxicity -Allergic reactions (rare in animals) -contrast medium- induced nephropathy (this is a reduction in renal function). The cause is poorly understood *avoid using nephrotoxic drugs with contrast media *only use in well hydrated patients It is generally accepted that the most effective means of increasing the safety of contrast media examinations is to use non-ionic media In animals the fatality rate has been estimated at 1 in 80 patients undergoing intravenous contrast medium injections. All veterinarians performing contrast studies should be aware of the associated risks and be prepared to provide emergency treatment as required. The use of intravenous fluids and supplemental oxygen appears to be the hallmark of treatment, and atropine and epinephrine should always be on hand.

Explain the different types of contrast media, their usage and safety

Contrast medium - alters the contrast of tissue or structures to help identify normal/abnormal anatomy -Used in radiography, U/S, CT and MRI Radiographic Contrast media is characterised by either being 1. Positive (increased opacity) e.g. barium sulfate, iodine based contrast solutions *these have a high atomic number so they absorb more x-ray photons then soft tissue 2. Negative (decreased opacity) e.g. air, CO2 or NO2 *Both CO2 and NO2 are more soluble than room air and are therefore are less likely to cause fatal air embolism, which has been reported in animals.

Discuss how x-rays are produced

Electromagnetic Radiation X-rays are produced when high-speed electrons strike metal. For radiography, this occurs in the controlled environment of an x-ray tube. An x-ray tube contains a positively charged target, the anode, and a negatively charged filament, the cathode, within a glass envelope. X-ray tubes provide for acceleration of electrons from their source at the filament to the metal target where x-rays are produced. -Different tissues absorb radiation more effectively then others (e.g. bone is much more effective than muscle). -Therefore absorption for different tissues varies even though the exposure is the same. -The magnitude of the difference between exposure and absorbed dose is the greatest for low energy photons and decreases as photon energy increases Radiographs are possible only because of differential absorption of x-rays by the patient; this provides contrast between different tissues in the image This differential absorption is caused by the dependence of absorption on the effective atomic number and physical density of the body part

Recognise some image artifacts and radiation safety violations - analog and digital FACTORS AFFECTING CONTRAST

FACTORS AFFECTING CONTRAST Radiographic contrast depends mainly on the relationship between kVp and mAs, and the amount of film fogging by scattered x-rays. 1. kVP and mAs relationship -Even though multiple combinations of mAs and kVp can result in a satisfactory radiograph in terms of film blackness, the contrast of the image will depend on the specific kVp-to- mAs combination selected High-contrast radiographs are also referred to as having a short scale of contrast because everything is either black or white. Low-contrast radiographs have few blacks and whites but many shades of gray; low-contrast radiographs are referred to as having a long scale A low mAs and high kVp technique will result in a lower contrast image (also called long scale) than one made with a high mAs and low kVp. 2. Film fogging The effect of fog is to reduce radiographic contrast. As discussed previously, fog produced by scattered radiation can be prevented by use of a grid, and radiographs made with a grid have higher contrast than those made without a grid. Film can also become fogged by exposure to pressure or high temperature, or by accidental exposure to light, such as results from a defective darkroom safelight or a faulty light seal around the darkroom door. Taking care to store and handle x-ray film safely will reduce fogging.

Recognise some image artifacts and radiation safety violations - analog and digital FACTORS AFFECTING IMAGE DETAIL

FACTORS AFFECTING IMAGE DETAIL 1. Motion -leads to image unsharpness -Reducing exposure time minimises the effect of motion -When exposure time becomes very short, the mA must be large; otherwise, the mAs will be too low to produce the necessary film blackness 2. Focal spot size -can be changed on some x-ray machines, if too small must use low mas to prevent overheating -With a large focal spot, edges of anatomic structures are projected more unsharply than with the small focal spot. This edge unsharpness is termed penumbra 3. Grids -When Compton scattered photons reach the film, they produce generalized exposure/blackness called fog. This reduces detail and contrast. Fog is increased by -Increased physical density of the patient -Increased total volume of tissue irradiated -Increased beam energy (kVp) Most of the scattered radiation can be removed before it reaches and fogs the film by a device called a grid. A grid is a flat, rectangular plate with alternating strips of an x-ray absorbent material, such as lead, and an x-ray transparent material, such as fiber, plastic or aluminum. -the mAs must be increased when a grid is used to ensure that adequate numbers of x-rays reach the cassette. 4. Distortion -Distortion is defined as unequal magnification of the part being radiographed. -Occurs when a part of the object is closer to the X-ray tube -As a result of the three-dimensional nature of patients, there will always be some anatomic distortion. To minimize the effect of distortion, it is important that patients are always positioned in a standard manner. One learns to recognize the normal pattern of distortion.

Peritoneal and retroperitoneal disease Peritoneal effusion What would I expect to see on X-rays?

Fluid in the intraperitoneal space is termed peritoneal fluid and fluid in the retroperitoneal space retroperitoneal fluid. Radiographically, increased fluid within the peritoneal cavity causes border effacement (as usually fat is providing contrast between organs) aka decreased serosal margin detail In many instances, the fluid is limited to the peritoneal space, and contrast between the kidneys and adjacent retroperitoneal fat is preserved. The more fat that is present, the more fluid that is needed to cause complete obliteration of serosal margins. A large volume of fluid will also cause abdominal distention with outward protrusion of the contour of the abdominal wall. The abdomen may also be somewhat pendulous in normal immature patients. A large volume of fluid may also displace the diaphragm cranially. If relatively mobile segments of bowel contain gas, they often float to the highest or uppermost area within the abdomen (Gas-filled bowel loops in a non-central location in patients with a large amount of peritoneal fluid suggest the presence of an abdominal mass or adhesions) Smaller amounts of peritoneal fluid, peritonitis, or carcinomatosis may produce a mottled, hazy, or irregular loss of contrast on survey radiographs. Individual viscera may be visualized, but the margins of soft tissue structures are indistinct or blurred. This can be localised to one region e.g. pancreas One method of assessing the abdominal cavity for fluid accumulation or peritoneal disease is to compare the contrast of the peritoneal versus retroperitoneal spaces as these should be the same.

Retroperitoneal Fluid and Masses Why can fluid look streaky? Most common cause of fluid?

Fluid in the retroperitoneal space can lead to alternating fat and soft tissue opacities (as the fluid fills in between the fascial planes) resulting in "streaking" The most common cause of isolated retroperitoneal fluid is haemorrhage (e.g. rodenticide toxicity, trauma) and Urine Retroperitoneal inflammation with increased fluid can also result from a migrating grass awn, a penetrating wound, ligatures from ovariohysterectomy, and perforation of the urethra during catheterization. Neoplasia and inflammatory masses can cause a soft tissue opacity in the retroperitoneal space -Lipoma is the most common primary tumour

Abdominal wall anatomy The 3 muscles it consists of are called..

From superficial to deep 1. External abdominus oblique (can be seen on X-rays due to fat either side) 2. Internal abdominus oblique 3. Transverse abdominus The last two are visible on X-rays as they are continuous with the ribs The cranial ventral abdominal wall thins, and ventral to the liver is often difficult to evaluate.

Module 1 Learning outcomes Discuss how x-rays are produced Describe how ionizing radiation affects the body and how to follow appropriate radiation safety guidelines Describe how exposure variables (kVp and mAs) change the appearance of the image Evaluate technique charts Recognise some image artifacts and radiation safety violations - analog and digital Describe the basics of digital imaging Discuss the principles of image interpretation Explain the different types of contrast media, their usage and safety

Hes a big fan of getting thoracic X-rays when you are taking abdominal ones e.g. patient comes in with a distended abdomen etc If a cat is coughing - think active inflammation e.g. infection, asthma Not coughing = Think pulmonary oedema The ascending colon is very short in cats Plylorus: if theres no gas in the stomach and there is no foreign material in the stomach, the pylorus should be gas filled on the L lateral

Abnormalities of the Adrenal Glands is cancer of these glands common? List the 3 most common neoplasias of the adrenal galnds

In cats and dogs, primary adrenal gland disease causing clinical signs occurs rarely Adrenal adenomas, adenocarcinomas, and pheochromocytomas are the most common lesions affecting the adrenal glands. Hemangioma and myelolipomas have been described in the adrenal glands of dogs, but they are rare. Malignant pheochromocytomas are the most aggressive adrenal gland tumors with invasion of the adjacent vasculature noted in 20% to 93% of dogs and metastasis in up to 40% of dogs With the advancement of imaging techniques, adrenal masses are more commonly diagnosed incidentally, which can be a dilemma. No current imaging modality can reliably differentiate benign from malignant adrenal gland lesions, and further evaluation of these patients for hypokalemia, hypertension, and loss of the hypothalamic-pituitary-adrenal response to a low dose dexamethasone stimulation test is recommended 1. Enlargement -An adrenal mass should be suspected when a soft tissue or partially mineralized mass is present craniomedial to a kidney. The kidney may be displaced caudolaterally by the mass. Differential Diagnosis for Adrenal Masses Adenoma Nodular hyperplasia Adrenocortical carcinoma May be: Metabolically inactive Cortisol secreting Aldosterone secreting Granuloma Metastatic neoplasia Pheochromocytoma 2. Mineralization -Radiographically visible adrenal calcification in dogs with Cushing syndrome is highly suggestive of neoplasia

Abdomen If ultrasound is available, sometimes abdominal radiographs are overlooked, and important findings are missed. Radiographs provide a global view of the abdomen that ultrasound cannot.

Learning outcomes 1. Identify disease of the peritoneal and retroperitoneal spaces 2. Describe the approximate normal size for the abdominal organs 3. Recognise organomegaly 4. Recognise normal stomach and intestinal positions and size 5. Differentiate paralytic from mechanical obstruction on radiographs 6. Discuss appropriate contrast media and technique for assessing gastrointestinal patency and morphology 7. Recognise radiographic features of common abdominal diseases

Peritoneal and retroperitoneal disease Peritoneal Metastasis and Steatitis

Looks like an ill defined granular/nodular pattern in the abdomen Examples of tumors associated with metastatic spread include hemangiosarcoma of the spleen and carcinoma of various abdominal organs -Carcinoma of the liver, pancreas, and intestinal tract commonly has peritoneal metastatic seeding in dogs and cats. Steatitis is the inflammation of fat causing saponification and fat necrosis. -Steatitis commonly occurs secondary to an inflammatory process (e.g., pancreas or gastrointestinal tract, abdominal neoplasia, or trauma1) or can be idiopathic. Steatitis caused by pancreatitis or pancreatic neoplasia in dogs and cats can result from the escape of proteolytic enzymes causing saponification of omental and mesenteric fat. Additionally, in cats steatitis can result from vitamin E deficiency and/or an excessive amount of polyun- saturated fatty acids in their diet.

What are the two most easily found lymph nodes on U/S?

Medial iliac and jejunal as these are the largest and most consistent Measuring maximal thickness or width of a lymph node is more reliable then measuring length to assess if too big Lymph nodes are often hypoechoic to isoechoic to surrounding tissue with a distinct cortex and medulla or homogenous echotexture. Ultrasonographically, abnormal lymph nodes enlarge and become more round and hypoechoic (abnormal lymph nodes in pictures)

Radiography of the peritoneum Can we see it?

No Analysis of the peritoneum is performed indirectly by assessing organ relationships and radiographic opacity of the abdomen.

Discuss the principles of image interpretation

ORIENTATION -Head (cranial aspect) of the patient is to the LEFT of the screen -VD or DV images have the cranial portion of the animal pointing up and the left side of the animal to the RIGHT of the screen -When viewing lateromedial or mediolateral radiographs of the extremities, including oblique projections, the radiograph should be oriented with the proximal aspect of the limb pointing up and the cranial or dorsal aspect of the limb to the interpreter's left. The relatively limited contrast resolution of radiographs means that the range of opacities visible radiographically can be described according to one of only five categories 1. air (or gas) opacity 2. Fat opacity 3. water (or soft tissue) opacity 4. bone (or mineral) opacity 5. metal opacity. Be careful about zooming in too close to an area (you tend to fabricate lesions) or viewing too small (tend to miss lesions) Beginners should have a standardized method of image interpretation, either working from the outside in, or the reverse. The best solution may be for beginners to work from a structured checklist.

What is perception artifact?

Perception is an important part of radiographic interpretation. Optimal illusions etc exist. Therefore what appears as an obvious finding to beginning radiologists may be incorrect because of a perception error. Only by viewing many radiographs, with continual feedback of experienced interpreters, can perceptual errors be minimized.

Abdominal Wall Abnormalities

Primary 1. Non neoplastic (hernia, dehiscence, inflammation, infection (e.g. secondary to a migrating FB), edema, subcutaneous emphysema, mineralisation) *Bladder and GIT is most likely to be displaced into wall defects -Tubular or round gas pockets summating with the abdominal wall can indicate herniated bowel loops *Mineralisation of the wall or soft tissues can be due to calcinosis cutis 2. Neoplastic -Lipomas are common -Fibrosarcomas can also occur in cats -Transitional cell carcinoma might spread to the abdominal wall secondary to percutaneous tissue sampling or surgery Abdominal wall disruption can be assessed on X-rays but better on CT or U/S generally

Peritoneal Masses

Primary neoplasia of the peritoneum is rare Primary peritoneal neoplasia includes mesothelioma, leiomyoma, or carcinomas where the primary origin is not identified Other differentials for peritoneal masses are like those for any mass and include cyst, hematoma, abscess, and granulomas.

Anatomy of the Peritoneum

The abdominal and pelvic cavities, in addition to the scrotum in male animals, are lined by the peritoneum. The peritoneum is a thin, serous membrane, which is divided into parietal, visceral, and connecting layers, Parietal: Covers the inner surface of the abdominal, pelvic, and scrotal cavities and is closely adhered to the abdominal musculature Visceral: A reflection of the parietal peritoneum onto the organs of the abdominal, pelvic, and scrotal cavities Organs in the abdominal cavity covered by visceral peritoneum are considered intraperitoneal. This includes the liver, gallbladder, spleen, pancreas, stomach, small and large intestines, as well as the ovaries in female animals. Most of the rectum in companion animals is in the peritoneal cavity; however, a short caudal segment is retroperitoneal before it ends at the anal canal. The peritoneal space or peritoneal cavity is the space between the parietal and visceral peritoneal layers and normally contains only a small amount of fluid for lubrication. The connecting peritoneum includes mesenteries, omenta, and intraabdominal ligaments. -The liver is attached to the diaphragm craniodorsally at the level of the caudal vena cava via the coronary, triangular, and falciform ligaments. -The stomach is fixed to the diaphragm and pylorus through the omentum. Additionally, the stomach and spleen are connected by the gastrosplenic ligament. , -The descending colon is connected to the spleen and therefore to the stomach. -the descending duodenum, pancreas, cecum and ascending colon are fixed in relationship to each other. Moreover, the proximal aspect of the ascending duodenum is connected to the descending colon by the duodenocolic ligament. -The mesenteric root is the site of the attachment of the mesentery to the dorsal abdominal wall, which commonly is located ventral to the second lumbar vertebra. The mesentery is the double layer of the visceral peritoneum suspending the intestine from the parietal peritoneum. The jejunum and ileum are not connected via ligaments to other structures in the abdomen and are therefore relatively mobile in the abdomen.

Pancreas - Anatomy

The body lies between the plylorus and the proximal descending duodenum The right limb of the pancreas lies adjacent to the descending duodenum. The left limb of the pancreas lies between the stomach and transverse colon

Compare retro with peritoneal Is the falciform ligament part of the peritoneum??

The falciform ligament is part of the peritoneum but the FAT is extra

How to minimise radiation Follow ALARA principles (as low as reasonably achievable)

The major variables used in adhering to ALARA are distance, time, and shielding. 1. Distance -Doubling the distance from the X-ray tube reduces exposure by a factor of 4 -Use chemical and physical restraint to minimise holding 2. Time -Minimise the number of views by ensuring staff know how to position and the patient is adequately sedated for views -rotation of staff 3. Shielding -Aprons and gloves should be inspected visually on an annual basis, and any portion that appears physically damaged should be evaluated radiographically for evidence of a crack. -the glove should cover the whole hand (not be laid on top) -as photons penetrating the cassette and table will strike the floor and be scattered back, also striking the hand *the shields only protect against scatter (they do not attenuate high energy x-rays), NOT PRIMARY BEAMS -collimate the beam

Blackness of the image

The more X-rays striking the film or X-ray plate, the blacker the image. This is directly related to the X-ray machine output (mAs). Film blackness is also affected by the energy of the x-ray beam, which is controlled by the kVp setting. (this is because higher energy x-rays are more likely to penetrate the patient) The distance of the tube from the X-ray plate also affects blackness (FFD) The lower the distance, the blacker the image (the equation is how to calculate the intensity difference if you change the distance). Example of how to do this in book.

U/S of pancreas What kind of echogenicity does the normal pancreas have?

The normal pancreas can be difficult to identify sonographically because of its small size, usually having an echogenicity like surrounding fat, and absence of a well-defined capsule The pancreas tends to be less echogenic than the spleen but more echogenic than the liver. (in cats its the same as the liver) A hyperechoic pancreas can be noted also in healthy dogs and dogs with hyperadrenocorticism

Finding the right adrenal gland..

The right adrenal gland is more difficult to image than the left, especially in larger dogs. After the cranial pole of the right kidney is scanned in a sagittal plane, the transducer is moved medially to find the caudal vena cava. The right adrenal gland lies dorsolateral to the caudal vena cava and cranial to the renal vein. More comma shaped

What is the retroperitoneal space?

The space between the dorsal margin of the parietal peritoneum and the abdominal wall is the retroperitoneal space. -it extends from the diaphragm to the anus -Organs included are adrenal glands, kidneys, ureters, major blood vessels, and lymph nodes. Additionally, the ventral aspect of the prostate gland in male dogs is retroperitoneal. The retroperitoneal space communicates cranially with the mediastinum through the aortic hiatus and caudally with the extraperitoneal aspect of the pelvic canal.

Example of Contrast optimization

The top radiograph was taken with factors most suitable for the thickest point so the nasal cavity has dropped out Contrast optimization allows us to see the thinner regions

How fast does peritoneal fluid absorb? e.g. if i had bleeding during a bitch spey, how long could I see this on imaging post?

Time is dependent on the properties of the fluid + the peritoneal membrane -Water, electrolytes, and low molecular weight fluids are normally absorbed by the peritoneal membrane within 24 hours -Proteinaceous fluids (such as, serum, blood, and lymph) are absorbed more slowly and may be present for 1-2 weeks *Static or increasing fluid accumulation in the post-operative period is abnormal. If complications are suspected, cytologic evaluation of the fluid will be necessary to differentiate between normal postsurgical fluid and fluid caused by septic peritonitis or other conditions.

Aspiration

Top picture "This amount of barium may not be clinically significant as much can be eliminated via coughing and mucociliary function."

Intraabdominal Mineral Opacity Common or uncommon? Also known as..?

Uncommon -focal lesions are thought to be the result of dystrophic calcification of necrotic mesenteric fat. Not clinically significant. -More common in cats then dogs and can be referred to as "bates bodies" Metastatic (not cancerous in this case) calcification can occur in previously normal tissue secondary to abnormal calcium metabolism, primarily in animals with chronic renal disease, or hypothyroidism. Common areas include blood vessels, kidneys and gastric mucosa -Rarely, peritoneal mineralization might be noted surrounding foreign material e.g. sponge or a mineralized fetus

Neoplasia of the Pancreas

Uncommon -not detected radiographically before they are very large The most common primary tumours are 1. Islet cell carcinoma compatible with insulinoma -Functional islet cell tumors may be benign or malignant and should be suspected in dogs with persistent hypoglycemia. 2. pancreatic adenocarcinoma The sensitivity of ultrasound for detecting pancreatic tumors varies and ranges from 28 to 75%

Describe the basics of digital imaging

WHAT IS DIGITAL RADIOGRAPHIC IMAGING? Digital radiographic imaging involves the following steps: (1) electronic measurement of the pattern of x-ray transmission through the patient, (2) conversion of the electronic measurement into a digital computer file, and (3) viewing the digital file on a computer monitor. In diagnostic medical imaging, the computer file is a Digital Imaging and Communications in Medicine (DICOM) format. The digital image comprises picture elements termed pixels. Each pixel has a specified shade of gray. The size of each pixel in a digital image determines the spatial resolution of the image; that is, how small of an object can be detected Bit depth Increased depth = more scales of grey Most digital radiographic systems range in bit depth from 10 to 16 (1024 to 65,536 shades of gray). Because the human eye can register only 50 to 100 simultaneous shades of gray, even with extreme manipula- tion of image contrast (postprocessing—see later), there is probably little benefit in generating images with more than 14- to 16-bit depth. CR vs DDR There are two main types of digital radiography acquisition hardware: computed radiography (CR) and direct digital radiography (DDR) CR -First in the market -The digital recording device is a cassette that contains a flexible imaging plate -The x-ray attenuation pattern of the patient is temporarily stored in the imaging plate -Therefore, the CR plate must be processed in a plate reader following radiographic exposure. DR -The detector replaces the film cassette, and within a few seconds after the radiographic exposure, the digital radiographic image is ready for quality-control evaluation. -Expensive to replace detectors

Describe how ionizing radiation affects the body and how to follow appropriate radiation safety guidelines

X-rays with energy of only 15 eV* can produce ionization of atoms. Ionization occurs when an electron is ejected from the atom (in this case by an x-ray). This creates an ion pair consisting of the negatively charged electron and the positively charged atom. When x-rays strike a person they can result in ionizations in DNA, leading to (1) mutations, (2) abortion or fetal abnormalities, (3) susceptibility to disease and shortened life span, (4) carcinogenesis, and (5) cataracts. This is why it is so important to minimize exposure of personnel working in a radiation environment. Why does a radiowave not cause damage but an X-ray does? -Energy levels are inversely proportional to wavelength and X-rays have a really small wavelength. The biologic effects of electromagnetic radiation are a function of the energy.

Describe how exposure variables (kVp and mAs) change the appearance of the image

mA = milliamperage This regulates the amount of electric current passing through the filament which in turn leads to more electrons being fired The number of electrons, and therefore the number of x-rays, produced is directly related to the mA setting on the x-ray machine control panel. kVp = Kilovoltage peak The electrons produced at the filament are accelerated to the metal target by applying a voltage differential between the filament and the target. The voltage difference between the filament and target is adjusted with the kilovoltage peak control. The energy of the x-rays produced is dependent on the energy of the electrons striking the target. Increases kVp in increases the acceleration which leads to higher energy X-rays Time The number of x-rays produced can also be controlled by the length of time that current is allowed to pass through the filament. The timer on the x-ray machine panel controls the length of time current is applied to the filament and is also the time that voltage is applied across the gap between the filament and target of the x-ray tube. mAs The milliampere second (mAs) is the unit that quantifies the amount of radiation produced A variety of combinations of milliamperage and time can be used to produce the same mAs value and thus the same number of x-rays

Clavicles dog vs cats

*always present in cats

4. Renal Mass lesions

-Neoplasia -Granulomas -Abscesses -Hematomas

tip 8 THIS IS A DIAGNOSTIC TEST

1/4th of the time we are wrong with imaging!! often lesions are hidden Be gentle on yourself you have to make mistakes to learn

Pt1 How many cranial vertebrae are there?

7

Bips Example

A cat given BIPS 12 hours before these radiographs were made. There is retention and clustering of the BIPS in the duodenum. This is highly indicative of an obstruction. There is reduced serosal contrast in the mid-right abdomen. Ultrasonographically, there was plication of the jejunum. At surgical exploration, several perforations had been caused by fishing line foreign material.

What is vestibulovaginal stenosis?

A developmental defect resulting from incomplete perforation of the hymen or hypoplasia of the genital canal and manifests as a narrowing at the vestibulovaginal junction Patients may be asymptomatic or experience chronic urinary tract infections, vaginitis, or incontinence.

Herniation in association with congenital diaphragmatic defects may occur at what age?

Any age! ..after abdominal trauma or transitory increase in intraabdominal pressure.

Tendon injuries 1. Shoulder

Bicipital tendon May see on X-rays 1. Chondromalacia of the intertubercular (bicipital) groove with osteophyte formation at its edges 2. Metastatic calcification of the biceps tendon. https://mediaspace.msu.edu/media/VM+516-+Canine+forelimb+muscles+and+tendons+palpation++%28cadaver+video%29/0_vy0s28om

Lateral pelvis

Bottom leg forward Put a foam pad between legs

Liver

Changes in hepatic size, shape, location, and opacity are used to assess the liver for possible abnormality

What is the normal diameter of the colon? Dogs: Cats:

Dogs: As a rule of thumb, the diameter of the normal canine colon should be less than the length of the body of L7 Cats: Should not exceed 2.2 times the small intestinal diameter, or 1.3 times the length of the fifth lumbar vertebral body

Tracheal masses

Dorsal displacement of the caudal thoracic trachea and carina is seen with left-sided cardiomegaly and ventral displacement with tracheobronchial lymphadenomegaly Also consider coagulation disorders compressing/displacing the trachea

Contrast UB

Filling defects can be free or attached These are free. You would also expect blood clots and gas bubbles to cause a similar appearance *All filling defects appear radiolucent when surrounded with positive-contrast medium*

Mediolateral hock Flexed or neutral?

Flexed is useful for OCD studies

This is the post emesis X-ray of the poll2 dog

Fluid present in the pylorus Gas in the duodenum Looks good!

Hydrocephalus What is this?

Hydrocephalus is excessive accumulation of cerebrospinal fluid (CSF) within the ventricular system of the brain. Congenital hydrocephalus occurs secondary to an interruption of CSF flow or defective absorption of CSF Canine breeds affected with congenital hydrocephalus include the Maltese, Yorkshire terrier, English bulldog, Chihuahua, Lhasa Apso, Chinese pug, toy poodle, Pomeranian, Pekingese, Cairn terrier, and Boston terrier. Hydrocephalus is less common in cats.1

Pelvic bladder

May or may not be related to clinical signs

L lateral same dog

Obstructed! and we can see foreign material in the pylorus

Collapse of the ...

Often won't be seen on X-rays

Ancillary factors Fat

One common example is the accumulation of mediastinal fat that is misinterpreted as a mediastinal mass in VD or DV radiographs Fat can also generally increase the opacity of the lungs due to superimposition

pt2.

Same for this circled area It is temping to call those black lines air bronchograms BUT they are not surrounded by an area of increased pulomary opacity - they are simply being outlined by adjacent vascular structures

A generally important takeaway from this course is the limitations of imaging (including U/S and advanced imaging). There is often overlap in the appearance of disease processes and sometimes on imaging a diseased organ may appear normal

Sampling is frequently needed for a definitive diagnosis - so be clear on explaining this to owners when pursuing imaging.

Lvs R

See the proximal duodenum - he says theres a band of tissue there - don't get tricked out by it, its just the pyloric sphincter

What is flail chest?

Segmental rib fractures involving the dorsal and ventral aspects of at least two adjacent ribs may create thoracic wall instability, resulting in flail chest.11,15 The flailing portion of the destabilized thoracic wall moves paradoxically to the normal thoracic wall; i.e., inward displacement during inspiration and outward displacement during expiration

Foreign bodies composed of mineral or metal are easily recognized. Small-sized rocks, clay litter, hard-shelled seeds, or other debris are ingested frequently by dogs and cats and opaque medicinal tablets may be administered by owners. These small mineral opacities are usually incidental and pass without causing obstruction. However what can they be an indicator of?

Small particles of radiopaque ingesta and debris can also accumulate proximal to a chronic partial obstruction Persistence of small opaque foreign objects in the same intestinal location in serial radiographs over a 24- to 48-hour period should increase the suspicion of partial obstruction.

Emphysematous cystitis.

Sonographic changes including linear hyperechogenicities with or without reverberation artifact, trapped in the urinary bladder wall and free in the urinary bladder lumen, can be seen.

What is the cingulum?

The vestibulovaginal junction, also termed the cingulum, is a normal slight narrowing between the vestibule and vagina.

Spinal interpretation There is no intervertebral disc between...

There is no intervertebral disc between C1 and C2 -C6 has proportionally larger transverse processes in the dog and horse that can serve as an anatomic landmark -In the dog and cat, the thoracic vertebra with a vertical spinous process is called the anticlinal vertebrae; this can be either T10 or T11 -The ventral aspect of L3 and L4 vertebral bodies in the dog may be relatively indistinct compared with other lumbar vertebrae and this can be confused with effacement from an aggressive process In most dogs and cats the sternum will have to be elevated slightly to position the sternum and spine in the same plane. high mAs-low kVp technique is recommended to maximize contrast and optimize the assessment of bone lesions.

Why would we do kidney U/S?

Ultrasonographic evaluation of the renal parenchyma is indicated at the first sign of renal dysfunction. Although ultrasound findings are usually not disease-specific, it allows differentiating acute and chronic renal changes, mass lesions, cysts, mineralizations, and alterations of the collecting system and ureters.

Is width or length of the adrenal gland more important?

Width! Adrenal gland length is proportional to body weight but the width is not *in one study incidental adrenal gland masses were identified in 9.3% of dogs undergoing an abdominal CT examination, and these masses were more commonly noted in dogs older than 8 years of age.

How do we do this?

*non caffeinated key. sprite great :)

Lateral skull

Make sure the eyes are on top of each other

Tips for dogs with short legs

Tape instead of sandbags!

What views do we need to assess the TMJ?

VD and 20 degree oblique lateral

Articular fractures

-Common in young animals because of the incidence of physeal and epiphyseal injury in these patients Because the proximal femoral physis is intra- capsular, all femoral capital physeal fractures are intraarticular fractures

Metal foriegn bodies in the stomach Tell me something about -Magnets -Zinc coins -Radiolucent metal

*Magnets in the stomach can cause ulceration *Zinc-containing coins can induce intravascular hemolysis and hemolytic anemia *Certain metallic foreign bodies are not metal attenuating on radiographs; for example, aluminum is relatively radiolucent

U/S ovaries

-Can be difficult to find on U/S - mobile and small. Some ovaries may contact the kidneys, whereas others will be several centimeters caudal, caudodorsal, or caudoventral to the kidney. The normal sonographic appearance of the ovary varies with the estrus cycle.

Urethra Anatomy

-Carries urine from the bladder (along with semen and reproductive secretions in the male) -Anatomically, the male urethra comprises three major areas: the prostatic urethra, membranous urethra, and penile urethra -The female urethra is shorter and wider than in males and entirely pelvic in location. The external urethral orifice lies caudal to the vestibulovaginal junction, where a muscular urethral sphincter is present

Caudocranial stifle

*palpate that the patella is central

Condyles should line up!

*sometimes you have to raise the hock up to make sure the tib and fib are in the same plane *palpate exactly where the stifle joint is -feel the tibial crest and the patella and centre just in from that point

Spine.

*the animal MUST be heavily sedated or GA Views -VD (not DV!!!). Spine wants to be closest to the plate -Lateral *even if your doing LS views, make sur ehte spine is straight from the caudal vertebrae to the cervical otherwise you will get some obliquity *Consider also a frog legged view for the sacrum

Craniolateral caudomedial 15-25 degrees - what is this good for!?

*this can be similar to the view you get if you don't get a proper craniocaudal ;) Useful for identifying OCD lesions in the articular surface of the medial humeral condyle + Medial coronoid abnomralities So do this view if worried about elbow dysplasia

Acute Gastric dilation

-Can be attributed to a range of causes -Gaseous distention of the stomach may also be caused by aerophagia as a result of severe dyspnea or pain With acute gastric dilation, the stomach is enlarged with gas but retains its normal position and anatomic relations -This can be determined by comparing right vs. left lateral views, and having a ventrodorsal view Recognition of the pylorus of a distended stomach is usually easier on lateral views than on the ventrodorsal or dorsoventral view *Large quantities of free peritoneal gas also tend to accumulate in the cranial abdomen - be careful not to mistake this for an enlarged stomach

GASTRIC DISEASES Displacement 1. Displacement with an intact diaphragm List two causes The stomach can be a good indicator of other surrounding organs being large/small Do abdominal masses that originate caudal to the stomach displace it cranially?

-If the diaphragm is intact, cranial displacement of the stomach relative to the diaphragm can occur only with a decrease in the size of the liver -Generalized hepatomegaly often produces caudal and dorsal displacement of the stomach *the cardia is relatively fixed compared to the rest of the stomach so the fundus often will not be too displaced. This is turn changes the axis of the stomach so its no longer paralell with the ribs The assessment of gastric displacement as an indicator of liver size becomes especially valuable when the liver is not visible because of emaciation or abdominal effusion. A: Abdominal masses that originate caudal to the stomach do not displace the stomach cranially because of the presence of the liver. Instead, such masses may distort the shape of the stomach as they press against and indent the stomach, or they may displace the stomach to the right or left. The relation of an abdominal mass to the stomach is often of value in helping define whether the mass originates in the liver, spleen, or pancreas

Radiography of the urethra Can it be seen in dogs? cats?

-In a normal dog, the urethra is not visible on radiographs. -Because of the more cranial position of the urinary bladder in cats, the prepelvic urethra may be seen if there is adequate surrounding fat to provide contrast.

Key points

-Label accurately -Ensure a complete study -Centre over the area of interest -For long bones ensure the joint above and below is included -Avoid movement blur! (especially for spine and skull - can't get away without heavy sedation or GA) *blind folds are a good idea for awake or sedated patients

Pharyngolaryngeal masses

-Lymphoma and SCC are the two most common neoplasias of cats in this region -In dogs tonsillar SCC is most common Mural masses tend to be smaller when clinical signs appear, given that their impact on the respiratory lumen is more direct. Thus, they can be very difficult to identify radiographically (endoscopy or direct visualisation may be more useful) Masses are characterized primarily by an increase in the normal soft tissue opacity, as with diffuse thickening, decreased margination of pharyngolaryngeal structures, and/or airway stenosis. Occasionally the mass will be well defined

Radiographic appearance of the diaprahgm

-Most of the thoracic surface is visible because of the adjacent gas-filled lungs. -A large portion of the abdominal diaphragmatic surface is not seen, because it silhouettes the adjacent liver. The ventral abdominal diaphragmatic surface is visible on the lateral view when fat is present within the falciform ligament. -Diaphragmatic structures that may be visualized distinctly radiographically are the right and left crura, the intercrural cleft, and the cupula (body) -On a lateral thoracic view made in extreme inspiration, the diaphragm is oriented more vertically; the shape changes from convex to straight. *Separate diaphragmatic structures are not seen as distinctly in the cat, probably because of the relatively small thoracic size

Craniocaudal

-Need to tilt the opposite side of the body -Foam pad under the olecranon helps to prevent slipping

Uterus normal appearance

-Normal uterus is not seen radiographically -Radiographic diagnosis of pregnancy is possible after fetal mineralization, which occurs from 43 days in the dog

Imaging of the ovaries

-Not seen when normal on radiographs *Focal areas of mineralization are commonly seen caudal to one or both kidneys in neutered female dogs and cats, representing dystrophic mineralization of the ovarian pedicles

Radiographic appearance of the pleura

-Not usually visible -Thin pleural lines between lobes are sometimes visible radiographically. Unless very wide (this can indicate pleural fibrosis) this is usually insignificant

Distinguishing a Mediastinal Mass From a Lung Mass

-Often not possible

Splenic masses

-Organs displaced depends on the location of the mass -Splenic masses are often sharply margin but may be obscured by peritoneal free fluid (e.g. haemorrhage) -A mass in the body or distal extremity of the spleen is a very common cause of a ventral abdominal mass, and on the lateral view results in dorsal and caudal displacement of the jejunum. -Masses of the proximal extremity of the spleen are less common than distal masses

Linear FB What can we expect to see?

-Poss the FB -Intestinal bunching -Undulating serosal border -Angular or crescent shaped gas bubbles in plicated bowel Hardest type of obstruction to diagnose. U/S really helpful for these

What are some other options to try and confirm a diaphragmatic hernia if i can't be sure on survey X-rays (or want to assess where the stomach and SI are)

-Ultrasound -removal of pleural fluid and repeat radiography of the thorax, - Oral barium *To ascertain the position of the stomach and proximal small bowel, a small amount (0.5 mL/kg) of barium sulfate (30% w/v) can be given orally and radiographs obtained after 15 to 20 minutes.

Caudoventral Mediastinal Masses

-Uncommon -CT is usually needed to differentiate caudoventral mediastinal masses from accessory lobe masses

Abnormal pregnancy X-ray findings

-Radiographic signs of fetal demise occur at least 24 hours after death, and are less reliable than sonographic indicators. The presence of gas within or around the fetus, overlapping of the bones of the cranium, a tightly curled fetus, and collapse of the fetal skeleton may be evident -Dystocia caused by fetal malposition, fetomaternal disproportion, or anatomic abnormality of the pelvic canal can be detected radiographically. Lateral and ventrodorsal views are recommended in dystocia patients where any of these are suspected. Fetal malposition is rarely a major problem in species that have large litter sizes. However, caudal, breech, lateral, or downward deviation of the head and transverse presentation can lead to obstruction within the pelvic canal. Occasionally, two fetuses will present simultaneously from each horn, which can also lead to dystocia. Feto- maternal disproportion is difficult to determine accurately. It generally occurs if the bitch has been bred by a much larger breed, if there is a single large fetus or in brachycephalic breeds where the head is large and the maternal pelvis flattened. If the skull or shoulders are wider on the ventrodorsal view than the pelvic canal, disproportion is the likely cause of dystocia.

Torsion of the testicle

-Rare -Usually secondary to a retained testicle that has turned neoplasitc Descended testicles that undergo torsion are usually non-neoplastic Structure enlarges. absent doppler signal

Pneumomediastinum Does this cause dyspnoea?

-Regardless of the amount of gas present, pneumomediastinum is rarely visible in VD or DV views because the overall size of the mediastinum is not increased, and the mediastinal gas is superimposed on the midline and obscured by other structures. -Lateral views will be most useful for detecting pneumomediastinum. -the only abnormality may be visualization of the adventitial surface of the trachea , or a heterogeneous radiolucent appearance to the cranioventral aspect of the mediastinum due to gas pocketing -Pneumomediastinum may progress to pneumothorax if mediastinal gas dissects through the mediastinal pleura into the pleural space. Conversely, pneumothorax does not progress to pneumomediastinum. Dyspnea usually is not seen with pneumomediastinum unless it results in pneumothorax. Because of the communication of the mediastinum with the neck and retroperitoneal space, pneumomediastinum may result in subcutaneous emphysema or pneumoretroperitoneum

Congenital radial head luxation

-Reported in a few breeds such as bulldogs and shi tzu's -FL lameness at ~4 months of age with reduced ROM of the elbow joint

Thoracic wall neoplasia Which is most common?

-Soft tissue tumours of the thoracic wall after common -Lipomas of the subcutaneous tissue are most commonly seen

The ddx for diffuse splenomegaly are listed above Can U/S echogenicity help differentiate these?

-Splenic congestion as a result of a phenothiazine and pentobarbital drug group results in splenomegaly with no associated change in echogenicity -Extramedullary hematopoiesis often results in generalized splenomegaly, with normal echogenicity, or a coarse or mottled appearance. Lymphoid hyperplasia can also have a diffuse mottled appearance. Splenic torsion, a form of splenic congestion, has a variety of appearances. Splenomegaly may be the only finding. However, splenomegaly with a diffuse hypoechoic parenchyma, separated by linear echogenicities that represent dilated hyperechoic vessels, is highly suggestive of torsion Complete absence of flow at the splenic hilus is also common, as is accompanying peritoneal fluid. Lymphosarcoma, mast cell tumor, malignant histiocytosis, leukemic infiltration, and multiple myeloma can all result in splenomegaly with normal or decreased echogenicity. A diffuse nodular pattern of small hypoechoic nodules, termed a Swiss cheese appearance, is suggestive of lymphosarcoma, but other tumors must also be considered

Splenic size

-Subjective as varies widely -Splenomegaly in the cat is considered if the distal extremity is visible on the lateral projection of the abdomen -In the dog, and to a lesser extent in the cat, generalized splenomegaly results in thickened, rounded, blunted margins, and dorsal and caudal displacement of the jejunum on lateral views

Normal Radiographic Findings Stomach List where the gas will be in L lateral R lateral VD DV

-The entire stomach may not be discernible on survey radiographs if it is empty or if the gastric fluid content silhouettes with the liver or other abdominal structures.

Caudocranial shoulder

-The leg needs to be extended out as much as possible *humerus paralell with table top Sore dogs may need heavy sedation You also need to roll the dog away slightly from the affected side so the scapula and humerus are clear of the chest wall

Hepatic U/S

-The liver has a moderately coarse texture and is usually hypoechoic to the spleen -Hepatic margins should be smooth and sharp but are better visualized sonographically if adjacent peritoneal fluid is present -Hepatic and portal veins are visualized routinely within hepatic parenchyma. -Portal veins are smoothly tapering vessels characterized by bright, echogenic borders -Hepatic veins are anechoic linear structures extending through the parenchyma (they go to the caudal vena cava) -The caudal vena cava can be visualized coursing through the liver in the right lateral abdominal quadrant. -The gallbladder is well visualized as an oval, anechoic structure in the right cranioventral portion of the liver *Intraluminal gallbladder contents are typically anechoic, although gallbladder sludge, which is dependent echogenic material without acoustic shadowing, is seen frequently. Although sludge is common in dogs with no indication of biliary disease, there is more recent evidence that it could be an indication of gallbladder dysmotility.

Radiographic Signs of Specific Cardiac Chamber Enlargement 3. Right atrium

-Uncommon -occasionally seen in dogs with tricuspid dysplasia. -When visible in the lateral view, right atrial dilation causes a bulge or mass effect in the craniodorsal aspect of the cardiac silhouette. However, dilation of the aortic arch and main pulmonary artery can also cause this radiographic appearance in the lateral view -In the VD or DV projection, an increased bulge in the right heart border from the 9 o'clock to 11 o'clock position may be present

Stomach Anatomy Do I sit infront of or behind the ribs?

-When empty the stomach normally lies cranial to the last pair of ribs or slightly caudal to the costal arch -The mucosal surface of the stomach is characterized by numerous folds or ridges called rugal folds. They are more distinct when the stomach is empty as they become flat when the stomach is expanded. -The fundus positioned dorsally on the left, and the pylorus ventrally on the right

RADIOLOGY OF THE SPLEEN

-The position of the spleen can vary widely (more so in the dog than cat) -Divided into the head (proximal part), body and tail (distal extremity) -The head is relatively fixed in the left craniodorsal part of the abdomen. The tail is not fixed -On VD views of the canine abdomen, the proximal extremity of the spleen is seen typically as a triangular soft tissue opacity caudolateral to the gastric fundus and craniolateral to the left kidney -The remainder of the spleen may extend caudally, adjacent to the left lateral abdominal wall, or more medially across the midline. When the spleen extends medially, the full length of the spleen is not visualized completely. -**On lateral views, the triangular soft tissue opacity of the proximal extremity of the spleen is located dorsally, caudal to the stomach. The distal extremity is visualized typically as a triangular soft tissue opacity immediately caudal and slightly ventral to the pylorus or liver ** =o i never had known this.. In both dogs and cats, it is important to realize that the entire spleen is rarely visualized on a single radiographic projection. When the x-ray beam is perpendicular to the spleen, there may be insufficient x-ray absorption to allow its visualization. When the x-ray beam is parallel to the long axis of the spleen, the resultant soft tissue opacity represents only a portion of the spleen.

What about OA/DJD for the coxofemoral joint?

-The presence of subluxation is a powerful indicator of the risk of development of coxofemoral degenerative joint disease *The most readily recognizable change is enthesophyte and osteophyte formation Pathologic alteration of subchondral bone may be detected as increased subchondral opacity of the weight-bearing surface -Affected joints exhibit decreased range of movement, which results in increased loading of the diminished weight-bearing surface. The combination of increased load, diminished sub- chondral strength, and loss of shock-absorbing cartilage results in altered shape of the subchondral bone table.

U/S of the spleen

-The splenic parenchyma has a uniform echotexture with a fine, dense pattern. -Echogenicity of the canine spleen is slightly greater than the liver and renal cortex -Renal cortical echogenicity of some normal cats may equal or exceed splenic echogenicity due to lipid deposition. -Splenic arteries are not usually seen without Doppler.

Calculi

-The urine/calculus interface is intensely hyperechoic and usually appears convex. Multiple calculi often aggregate together and give rise to an irregular, somewhat continuous surface, which makes distinguishing and measuring individual calculi difficult. Echogenicity and acoustic shadow generation are independent of chemical composition, so radiopaque and nonradiopaque calculi can be detected by sonography. Gas bubbles introduced accidentally by urinary bladder catheterization or cystocentesis appear echogenic and can generate acoustic shadows or reverberation artifacts. Differentia- tion from calculi is easy because the bubble floats on top of the urine. *The cranioventral aspect of the bladder is most likely to be thickened in cystits cases* Crystalline and cellular sediments generate a variably echogenic pattern in more dependent urine. In cats, the crystal- line deposits may become thick enough to form a hyperechoic layer confluent with the urinary bladder wall that creates acoustic shadowing. Ballottement or changing patient position can differentiate the swirling sediment from calculi.

U/S of the uterus

-The uterine body can be located most easily by scanning between the bladder and caudal aspect of the descending colon -It appears as a tubular echogenic structure, similar in size to a loop of intestine. It is differentiated from intestine by location and absence of distinct wall layering. *the uterine lumen is not typically seen -In anestrus, the uterine wall is thinnest with no fluid present. A small amount of hypoechoic to anechoic fluid can be present during proestrus and estrus when the endometrium is thickened mildly, or as a transient finding in the period immediately after mating

Abnormal U/S uterus

-The uterine stump and cervix are accessible sonographically by imaging lateral to the caudal aspect of the urinary bladder. The uterine stump is rarely seen if normal Progesterone-related stump pyometra can occur only if the ovaries or ovarian remnants have been left in situ, permitting ongoing estrus cycling. However, stump granuloma and abscessation can occur secondary to local inflammation and infection independent of the presence of progesterone and can occur as a reaction to nonabsorbable suture material. A granuloma typically appears as a focal echogenic mass, typically mildly heterogeneous, adjacent to the bladder neck.

1. Destruction of the cortex

-The x-ray must be tangential to the lesion to see cortical destruction (otherwise it will just look more radiolucent) -Purely medullary bone loss does not mean that the lesion is not aggressive; it means only that one feature of lesion aggressiveness is not present. -Bone lysis can be subclassified as geographic, moth-eaten and permeative In a nonaggressive bone lesion, the cortex may be uninvolved, or it may be expanded without destruction. Bone lesions can appear serious, but without a sign of aggressiveness they can be considered to be benign. It is important not to jump to a conclusion about a bone lesion until it has been scrutinized carefully for all radiographic criteria of aggressiveness.

OA/DJD in cats

-There is poor correlation between radiographic signs of degenerative joint disease in older cats and associated clinical lameness. -Similar signs to dogs however less joint effusion seen and generally more calcification

Hip dysplasia in dogs

-Typically bilateral but can be asymmetric -Heritability estimates range from 0.2 to 0.6 -Overnutrition is one of the principal nongenetic factors that influences expression of canine hip dysplasia The earliest changes of hip dysplasia cannot be seen radiographically (synovitits) however the strongest clue to their presence can be obtained by testing for signs of joint laxity *at least half the femoral head should lie medial to the dorsal acetabular margin Subsequent radiographic changes are those of degenerative joint disease developing as (1) perichondral osteophyte formation, (2) remodeling of the femoral head and neck, (3) remodeling of the acetabulum, and (4) increased opacity of subchondral bone of the femoral head and acetabulum A line of enthesophytes on the caudal aspect of the femoral neck, termed the Morgan line, has been described as an early sign of coxofemoral degenerative joint disease The predictive value of the distraction is constant after 6 months of age, thereby providing valuable information to breeders at an early age when selecting breeding dogs

Normal U/S findings stomach How many layers of the stomach are there??

-When empty, the stomach may have a wagon-wheel appearance because of folding of the rugal folds -The stomach has 5 layers : mucosal surface, mucosa, submucosa, muscularis propria, and subserosa/serosa The innermost aspect of the gastric wall is hyperechoic and corresponds to the luminal surface of the mucosa, followed by the hypoechoic mucosa In the stomach, the mucosa and muscularis are often of similar thickness, which is different to the small intestine where the mucosa is usually the thickest layer. The stomach wall thickness in dogs is 3 to 5 mm depending on the location and size of the dog

Pleural fluid

-You can't tell an exudate from a transudate on radiographs however an exudate may be more asymmetrically distributed -In DV the fluid will move ventrally and silhouette the heart -In VD its easier to see the heart Pleural fluid is usually relatively equally distributed between the right and left pleural spaces. Some patients, however, have asymmetric fluid distribution. Causes of unilateral or asymmetric pleural fluid include a difference in compliance between lung lobes, the closing of mediastinal fenestrations from inflammation or a mass, and an anatomically complete mediastinum. Pyothorax is a common cause of unilateral or asymmetric pleural fluid because of the viscid nature of the exudate but other types of fluid can also be asymmetric. Chronic pleural fluid, or an inflammatory effusion, often results in extensive pleural fibrosis. When the visceral pleura is fibrotic, the margin of the retracted lung assumes a rounder shape than normal because of altered compliance. This appearance is typical of pleural fibrosis, which limits the ability of the lung to both expand and contract because of elastic recoil.

Nasal tumours

-account for 1-2% of all neoplasia -Nasal cavity tumors have an aggressive radiographic appear- ance, with bony invasion and loss of conchal detail being common radiographic features. -May cause soft tissue increase -May be unilateral or bilateral Nasal tumors may result in increased opacity within the frontal sinus.71,82-84 It is usually impossible to determine on radiographs whether frontal sinus opacification is caused by tumor extension or by occlusion of the nasofrontal com- munication with subsequent mucus accumulation in the sinus. The most useful radiographic views for evaluating nasal disease include the intraoral dorsoventral and/or the open-mouth ventrodorsal view for detailed evaluation of the nasal cavity without superimposition of the mandible (Fig. 11.11). The open-mouth ventrodorsal view is better for cribriform plate assessment, because a radiographic film cassette or digital plate cannot be inserted adequately caudally to include the cribriform plate in the intraoral view. The rostrocaudal frontal sinus projection is necessary for evaluation of individual frontal sinuses

A and B Where are the osteophytes?

-altered fat pad -Perichondral osteophytes and enthesophytes are visible on the distal femur and proximal tibia.

How is the cat spleen different on X-rays?

-smaller, thinner and more fixed in position -Like the dog, the proximal extremity of the spleen can be visualized on VD views in the left cranial abdomen, caudolateral to the stomach and cranio- lateral to the left kidney. -On VD views, the distal extremity usually extends caudally along the left lateral abdominal wall, but the amount of spleen visualized varies depending on body fat, positioning, gastric contents, and splenic position. -On lateral abdominal views in the cat, the proximal extremity may be visualized caudal and dorsal to the gastric fundus. The distal extremity of a normal spleen is rarely visualized in the cat. In 100 cats with a presumably normal spleen, the distal extremity was visualized on a lateral radiograph in only one cat.

Normal radiographic appearance of the thoracic wall How many ribs and sternebral segments are there

-soft tissues of the thoracic wall are usually homogenous -in obese animals you may see the extracostal muscles -13 ribs -8 sternebral segments

What are lung bullae?

-usually benign - result from previous trauma or a congenital lung malformation

Diffusely increased splenic echogenicity is less common but may be seen with..

1. Chronic vascular compromise 2. Peritonitis 3. infection 4. Diffuse nonneoplastic infiltrative disease, such as extramedullary hematopoiesis

List 5 Advantages of digital imaging

1) Reduced expendable supply cost and elimination of darkroom maintenance 2) Contrast optimization and exposure latitude -When one begins to evaluate digital radiographic images compared with analog film radiographic images, the initial impression may be that of improved detail in the digital radiograph. This is a misconception created by the excellent contrast optimization that characterizes digital radiographs. What is Contrast optimization? Defined as: the ability of an imaging system to display thick and thin regions, and regions of low and high atomic number, suitably in one image -Also termed contrast resolution, is a feature of digital radiography that is related to the bit depth of each pixel and the processing software that accompanies the digital- imaging system. The processing software can assign a gray shade to a pixel in a digital image that would have been either black or white in an analog image. This results in more of the image having interpretable gray shades and not appearing overexposed (black) or underexposed (white). -With radiographic film, radiographic contrast is associated rigidly with the relationship between kilovoltage peak (kVp) and mAs However in digital the computer can assign a suitable gray shade to pixels meaning differences in thickness of the animal are much less obvious in digital radiographs than in analog radiographs -The ability of a radiograph, whether analog or digital, to display differences in x-ray absorption between various tissues or organs is termed contrast resolution. In short contrast optimization is additional processing that 'normalizes' the image -dark regions are made lighter and lighter regions are made darker Digital radiographs don't actually have more detail then Film but they look that way because of contrast optimization What is exposure latitude? The ability of digital plates to compensate for either high or low kVp-to-mAs combinations that would result in overexposure or underexposure in an analog system. -The magnitude of the range of radiographic exposures that can be used to create a diagnostic radiographic image is called exposure latitude. -One disadvantage of wide exposure latitude is exposure creep, where unnecessarily high exposure factors are not recognized as they would be when using an analog system. -Most digital radiography manufacturers have incorporated an exposure index (EI) metric that enables the user to evaluate the amount of incident radiation that strikes the plate (i.e., the exposure factors) and this EI can be used to judge whether radiographic techniques are too high or too low. What happens in digital radiography if the image is overexposed or underexposed? Underexposed: May appear grainy (this is because the computer is having to interpolate more of the image) This is also called "noise" so generally rather then becoming white, they will be grainy Overexposed: Parts will appear blacker (rather then the whole plate as with analog) The plate becomes "saturated" and parts of anatomy "disaepear" 3) image postprocessing, ability to adjust image blackness and contrast after exposure High contrast X-rays are generally desirable for the abdomen where tissue contrast tends to be minimal (provided by fat between the abdominal organs) In the thorax low contrast tends to be preferred as the inherent patient contrast is high (provided by air in the lungs) *so its important the right algorithm is selected for postprocessing 4) improved image accessibility and consolidated image storage 5) enhanced portability enables consultation 6) an opportunity to change the imaging paradigm

Anatomy of a vertebrae What do we consist of?

1. A body aka the centrum -Other than the first cervical vertebra, each vertebral body is narrowed centrally and has cranial and caudal endplates that unite with an interposed intervertebral disc. The anatomic structure of C1 (atlas) and C2 (axis) is complex and differs widely from the remainder of the vertebra 2. The vertebral arch -this has paired right and left pedicles and laminae and the unpaired spinous process. -The vertebral arch bounds the vertebral canal, which houses the spinal cord. -The articular processes of the lamina form the synovial joints along the dorsum of the vertebral column *the transverse processes fit in here somewhere.. (possibly coming off the pedicle? In the cervical region, the articular processes are oriented in an oblique plane, summating the intervertebral foramina and vertebral canal. In the lumbar region, the articular processes lie in a dorsal plane and do not summate the foramina and canal.

Diffuse Diseases of the Stomach Wall

1. Acute gastritis -rarely seen radiographically -has a range of causes including exercise induced *associated with a high morbidity and mortality in working dogs and sled dogs. 2. Chronic gastritis -diagnosed infrequently -Examples include chronic atrophic gastritis, chronic hypertrophic gastritis, eosinophilic gastritis The above often can't be diagnosed by radiographs. - Radiographically absent or diminished rugal folds, large rugal folds, nodules, or a thickened gastric wall may be seen with these diseases -Care must be taken when evaluating stomach wall thickness on survey radiographs. Fluid within the stomach may cause border effacement with the stomach wall, creating the illusion of increased thickness. Ultrasonographic findings of inflammatory disease of the gastric wall are similar to those reported for gastric tumors and can range from increased gastric wall thickening with normal wall layering or loss of wall layer definition to altered echo- genicity of the gastric wall. 2. Soft tissue calcification of the gastric wall -can be seen with chronic renal failure -uremic gastropathy can cause thickening of the wall as well + gastric lesions

Many variables are known to influence facture healing adversely List 5 he incidence of nonunion fracture in dogs is approximately 3.4%28 with a range of 0% to 6%.

1. Age and weight of the patient, 2. Quality of anatomic reduction 2. stability of fracture -this is the most common cause of fracture healing failure in animals -movement can disrupt blood supply and disrupt new tissue 3. Extent of local blood supply 4. Type of fracture 5. Bone involved 6. Presence of infection 7. iatrogenic interference 8. systemic diseases (such as, metabolic and endocrine diseases), pathologic fracture, corticosteroids, and use of nonsteroidal anti-inflammatory drugs *Hypothyroidism, hyperparathyroidism, diabetes mellitus, and some paraneoplastic syndromes can delay bone healing. 9. Nutritional status

DISORDERS PRIMARILY AFFECTING BONE

1. Agenesis or hypoplasia -usually inherited or due to in utero factors -the limb is usually malformed or shorter then usual 2. Polymelia -polydactyl cats are an example of this. The finding is usually clinically insignificant 3. Nutritional secondary hyperparthyroidism 4. Osteogenesis imperfecta -rare defect in collagen -similar radiographic signs to nutiritonal secondary hyperparathyroidism. -teeth may be pink 5. Panosteitits 6. Osteopetrosis -Rare inherited bone disease -Increased opacity of bone. As the medulla is taken up animals develop anaemia

How many thoracic vertebrae are there?

13 The anticlinal vertebra is a point in the caudal thoracic vertebral column at which vertebral anatomic features change. It may be used as a point of reference in diagnostic imaging studies. -usually t11

DV vs VD radiograph of the thorax

1. Caudal lobe pulmonary vessels are more conspicuous in DV 2. The cardiac silhouette changes - The rounder appearance and displacement to the left that occur normally in DV radiographs are commonly misinterpreted as cardiomegaly

Epiphyseal dysplasias

1. Congenital hypothyroidism -rare -clinically, the animals are disproportionate, short-limbed dwarves with bowed limbs and long necks and trunks. -Radiographic findings consist of epiphyseal dysplasia that appears as reduced or delayed ossification of the epiphyseal cartilage model. 2. Mucopolysaccharidosis -Clinical manifestations include disproportionate dwarfism and facial dysmorphia, which includes a broad maxilla, widespread eyes, a flat nose, and short ears. Hyperextension of the distal extremity joints occurs as a result of joint laxity. -Generalized epiphyseal dysplasia is present 3. Multiple Epiphyseal Dysplasia of Beagles -characterized by a failure of normal epiphyseal ossification -affected individuals have stunted growth -Anticipate hip dysplasia in the future along with DJD in other joints

Give differentials for diffuse splenomegaly Is splenomegaly in the cat likely to be benign?

1. Congestion (e.g. GDV) 2. Infectious (inflammation caused by toxoplasmosis, fungal organisms, Mycoplasma haemofelis, ehrlichiosis, chronic bacteraemia) 3. systemic lupus erythematosus 4. Portal hypertension 5. Splenic torsion/ infarction 6. Anesthetic drugs 7. Infiltrative disease (e.g., primary and metastatic neoplasia, and extramedullary hematopoi- esis). 8. Chronic hemolytic anemia Splenomegaly in the cat is less likely to be benign, because the feline spleen is considered nonsinusoidal and less capable of storing large amounts of blood

Causes of pleural fluid

1. Congestive heart failure 2. Pyothorax 3. Lung or pleural tumor 4. Trauma 5. Coagulation defect 6. Hypoproteinemia 7. Mediastinitis 8. Idiopathic chylothorax 9. Diaphragmatic hernia

Changes between a R and L thoracic lateral

1. Cranial lobe vessels -The pulmonary artery and vein in the right cranial lobe are used commonly as a basis for assessing the pulmonary circulation. -Much easier to assess in a L lateral (so L is best for the pylorus and the lobe vessels..) The left cranial lobe pulmonary vessels cannot usually be assessed or compared accurately in either the left or right lateral view, because they are located more dorsally in the thorax and usually superimposed on other vessels or the thicker dorsal portion of the mediastinum. Occasionally, pulmonary artery/pulmonary vein pairs can be compared in DV or VD views, but assessing the right cranial lobe vessels in the left lateral view should be a standard aspect of thoracic radiographic interpretation in the dog and cat. 2. Diaphragm -In the left lateral view, the two dorsal crura of the diaphragm deviate from each other, whereas in the right lateral view they are more parallel In the right lateral view, the dependent right crus will be cranial to the left crus because of pressure from abdominal contents. Vice versa for L 3. Heart will appear slightly different (more rounded in L lateral)

Mural changes

1. Cystiits -thickening of the bladder wall -frequently hyperechoic intraluminal material -Small polypoid mucosal masses are also occasionally observed with chronic cystitis. Muscular hypertrophy resulting from chronic partial lower urinary tract obstruction can also mimic cystitis wall thickening.

List 5 radiographic signs of megaoesophagus

1. Dilatation of the esophagus with gas 2. Retention of food or fluid 3. Tracheal stripe sign 4. Visualization of the longus colli muscle 5. Ventral displacement of the intrathoracic trachea, ventral displacement of the heart 6. Aspiration pneumonia

Pyloric obstruction/. What are the classic signs?

1. Direct visualisation of pathology within the pylorus -depends on radiolucency of the object -depends on other gastric contents 2. Moderate to severe gastric distension with fluid or gas -depends on chronicity -depends on amount of v+

3 questions he asks for if this pet needs surgery

1. Do i see a FB? 2. Do I see evidence of an obstruction? 3. Does my interpretation match my patients clinical picture? He sees surgery as diagnostic as well as therapeutic

What are radiographic signs of hydrocephalus?

1. Doming of the calvaria 2. Cortical thinning 3. Persistent fontanelles 4. a homogeneous appearance to the brain, resulting from the loss of normal convolutional skull markings Radiographs are insensitive for detection

What are clinical signs related to esopheageal disease (list 4)

1. Gagging 2. Retching 3. Regurgitation 4. Painful swallowing or inability to swallow Signs developing secondary to esophageal disease include pharyngeal and upper airway inflammation, nasal discharge, weight loss, pneumomediastinum, pneumothorax, pleural effusion, and aspiration pneumonia. *Rarely you can get non cardiogenic pulmonary oedema

CHANGES IN GASTRIC SHAPE AND SIZE List 3 causes of this

1. Gastric dilation 2. Gastric dilation and volvulus 3. Outflow obstruction

Bacterial bone infections What are the two main ways of getting bacterial osteomyelitits? which is more common

1. Haematogenous -dogs > cats -typically young dogs, perhaps immunosupressed 2. Direct inoculation e.g. bite, fracture, surgery The latter is far more common Osteomyelitis resulting from direct inoculation has no predilection for skeletal localization and lesions develop at the site of injury Lesions tend to be metaphyseal (due to rich capillary blood supply) Lysis or production can predominate

Radiographs alone are generally inadequate to say what the cause of hepatomegaly is. List some causes of generalised hepatomegaly

1. Hepatic congestion 2. steroid hepatopathy 3. hepatic lipidosis 4. inflammatory and infiltrative disease, 5. primary and metastatic neoplasia

What are causes of megacolon?

1. Idiopathic 2. chronic constipation and obstipation from nutritional, mechanical or metabolic causes -mechanical causes can be due to pelvic narrowing from trauma, tumours, enlarged prostate.. 3. Spinal anomalies such as cauda equina syndrome or sacrocaudal agenesis in Manx cats 4. Neuromuscular disorders 5. Metabolic disorders such as hypoka and hypothyroidism

What are the radiographic signs of the alveolar pattern?

1. Increased soft tissue opacity (can be intense) -Intense alveolar disease causes loss of visualization of the pulmonary vessels and bronchial walls (due to silhouette sign) 2. Air bronchograms (hallmark sign) -does not HAVE to be present though *the opacity of the normal lung and bronchi on X-rays is similar so you can't normally see smaller bronchi 3. The lobar sign

What are radiographic signs of joint disease?

1. Increased synovial volume 2. Altered thickness of the joint space 3. Decreased subchondral bone opacity 4. Increased subchondral bone opacity 5. Subchondral bone cyst formation 6. Altered perichondral bone opacity 7. Perichondral bony proliferation 8. Mineralization of joint soft tissues 9. Intraarticular calcified bodies 10. Joint displacement or incongruency 11. Joint malformation 12. Intraarticular gas

Diseases of the collecting system List some causes for distension of the renal pelvis AKA pyelectasia

1. Increased urine production e.g. diuretic therapy, IVFT, kidney disease 2. Congenital malformations e.g. ectopic ureters, ureterocele 3. Lower urinary tract obstruction or infection e.g. pyelonephritis

Bronchial Pattern He thinks this is the easiest of all the pulmonary patterns What is the radiographic appearance?

1. Increased visualization of the bronchi -thickened walls -Peribronchial cells or fluid This creates ring shadows or tram lines There is an generalized increase in opacity but it is not as intense as an alveolar pattern (because theres simply not that many bronchi!)

Anatomy of the Humerus

1. Infraglenoid tubercle of scapula 2. Head of humerus 3. Anconeal process of ulna 4. Lateral epicondyle of humerus 5. Tuber olecrani 6. Medial epicondyle of humerus 7. Lateral coronoid process of ulna 8. Proximal radioulnar joint 9. Medial coronoid process of ulna 10. Head of radius 11. Condyle of humerus 12. Proximal physis of humerus 13. Greater tubercle of humerus 14. Supraglenoid tubercle of scapula

Causes of pneumomediastinum

1. It is common for air to escape into the pulmonary interstitium from sites of intrapulmonary alveolar rupture that do not involve the visceral pleural surface of the lung This phenomenon called the Macklin effect after its discoverer, is a relatively frequent occurrence following blunt thoracic trauma, such as an automobile accident, and also after iatrogenic pulmonary hyperinflation during anesthesia or resuscitation. Pneumothorax is not present when pneumomediastinum results from the Macklin effect unless the visceral pleura becomes torn or the mediastinal air accumulation extends to the pleural space. 2. Another common cause of pneumomediastinum is dissection of gas in fascial planes of the neck caudally into the mediastinum. Gas in the neck commonly results from neck trauma, such as a bite wound. Intrafascial cervical gas can also result from a tracheal perforation. In cats it is common for the trachea to be perforated inadvertently during jugular venipuncture, and this can lead to air leaks and pneumomediastinum as gas tracks down the neck. -cuff over inflation is another cause of this Development of subcutaneous emphysema occurs quickly following tracheal rupture from cuff over distention. If subcutaneous emphysema develops during a surgical procedure, the anesthetist must be aware of this potentially fatal complication. Other less common causes of pneumomediastinum are esophageal perforation as a result of trauma, neoplasia, or inflammation; extension of retroperitoneal gas into the mediastinum; and presence of a gas-producing organism in the mediastinum.

Atelectasis -This tends to not be a primary disease, usually secondary to something else such as..

1. Lateral recumbancy 2. Bronchial obstruction 3. Pleural disease (compresses the lung and squeezes the air out of the alveoli) e.g. pleural effusion, pneumothorax The lung lobe will be decreased in size and increased in opacity There will be an ipsilateral mediastinal shift In the LEFT picture L lung has increased opacity and air bronchograms however the cardiac silhouette is also shifted to the left This makes us suspect its atelectasis Right image - dog 10 minutes later after right recumbancy Heart is back to normal positioning

What are 3 conditions that cay increase the Size of Both Pulmonary Arteries and Pulmonary Veins

1. Left-to-right shunt -Patent ductus arteriosus -Ventricular septal defect -Atrial septal defect 2. Peripheral arteriovenous fistula 3. Iatrogenic intravenous fluid overload 4. Fluid retention secondary to decreased cardiac output

What can sequelae of a chronic bronchial pattern be?

1. Lobar collapse (e.g. R middle lobe in asthmatic cats) 2. Bronchiectasis 3. spontaneous rib fractures 4. pulmonary hyperinflation 5. bronchial mineralization (more likely in cats or dogs with hyperA) Chronic bronchial inflammation can lead to excess endobronchial exudate or mucus, and if this results in bronchial obstruction, lobar atelectasis will occur secondary to reabsorption of air trapped distal to the obstruction.

Although bacterial bone infections and bone tumors both result in aggressive bone lesions, the lesions usually have little in common Why? Compare and contrast

1. Location -Bone lesions from osteomyelitis in dogs and cats are typically not metaphyseal in location, because most are associated with direct inoculation. 2. Signalment -Bacterial osteomyelitis lesions that are hematogenous are usually polyostotic and occur in young dogs and therefore are not typical for a neoplastic disease. 3. Periosteum -Most lesions of bacterial osteomyelitis will have a periosteal reaction that is less aggressive than with a neoplastic lesion, where spiculation is more common. -Periosteal reactions with osteomyelitis often have a palisading or columnar appearance, in which vertically oriented columns of new bone are oriented perpendicular to the cortex but a columnar periosteal reaction can sometimes be found with neoplastic bone lesions as well

Classifying fractures

1. Location -which bone -diaphyseal, metaphyseal, epiphyseal -if the physis is open then use salter harris descriptors 2. Direction -transverse, oblique, spiral 3. Complete vs incomplete 4. Number of fracture lines -simple vs comminuted -Comminuted fractures with three large fragments often have a triangular fragment called a butterfly fragment 5. Open vs closed 6. Dispacement -Displacement of a fracture is described in terms of the distal or caudal fracture fragment. In some fractures, the fragments are moveable and change position easily -Shortening of the bone is most commonly a result of traction by surrounding musculature and may be a result of collapse of multiple fragments or overriding of the main fracture fragments. Lengthening of the bone, caused by distraction of the fragments resulting in widening of the fracture gap, is uncommon except with avulsion fractures

Complications of fracture repair

1. Malunion -fracture has healed but have abnormal alignment -Long bone malunion fractures can be classified as valgus, varus, antecurvatum, recurvatum, torsional, or translational 2. Delayed union is a subjective classification in which a fracture is healing but not as quickly as expected. -There is not a rigidly defined fracture healing time because of the multiple factors involved, including age, breed, location, type, soft tissue status, defects at the fracture site, and the type of fixation used. 3. Nonunion is a fracture that is not healed and has no evidence of progressive healing that would result in a bony union. Some long-term nonunion fractures may develop into a pseudoarthrosis because of chronic motion at the fracture site, but this is uncommon. Fibrocartilage fills the fracture gap, and there is a fibrous capsule filled with serum. The patient may have good use of the limb and not have significant pain after formation of the pseudoarthrosis. Many of these are incidental findings and result from unrepaired fractures. In other instances, there is formation of dense, fibrous, and cartilaginous tissue that stabilizes a fracture forming a firm fibrous union. In this instance, a radiolucent gap or line remains at the fracture site that may or may not opacify over time. A common site for fibrous union fractures is in the equine distal phalanx.

In general, the appearance of mechanically obstructed bowel differs from functionally obstructed bowel by the following parameters List 3

1. Mechanically obstructed bowel is usually of larger diameter than functionally obstructed bowel 2. Both gas and fluid are typically in the lumen of mechanically obstructed bowel, whereas functionally obstructed bowel tends to contain more gas or may be completely gas filled 3. Patients with mechanical obstruction usually have some bowel segments of normal size, whereas patients with functional obstruction may have generalized involvement of the bowel. *These are only guidelines and radiographic distinction is impossible in some patients *

Touch your own styloid process of the ulna =o

1. Medial epicondyle of humerus 2. Medial coronoid process of ulna 3. Body of radius 4. Distal metaphysis of radius 5. Distal epiphysis of radius 6. Intermedioradial carpal bone 7. Sesamoid bone of abductor pollicis longus 8. Ulnar carpal bone 9. Distal epiphysis (styloid process) of ulna 10. Distal metaphysis of ulna 11. Body of ulna 12. Head of radius 13. Elbow (cubital) joint 14. Lateral epicondyle of humerus

Differentials for focal hepatic masses include..

1. Neoplasia 2. Hepatic abscess 3. Granuloma 4. Hepatic cyst

Where are the most common locations of OCD in the dog? Try for 5 areas

1. The caudal aspect of the proximal humeral head 2. The distomedial aspect of the humeral trochlea 3. The lateral and medial femoral condyles 4. the femoral trochlea 5. The medial and lateral trochlear ridges of the talus Lesions are frequently bilateral but animals may only have clinical signs in one limb

Views for atlantoaxial instability

1. On a routine lateral radiograph, the dens is masked by the sheer mass of the atlas. -Making a left 15- to 30-degree ventral/right dorsal radiograph will reduce osseous superimposition on the dens and help identify fractures and malformations. Even with this view, small fractures may not be apparent. 2. Questionable. VD projections can also be made, but there is the risk of exacerbating the spinal cord compression, especially in anesthetized patients. -The VD projection is unnecessary to confirm atlantoaxial subluxation. The lateral radiographic view is usually diagnostic and two typical findings should be identified: • If subluxation is present, the axis is displaced dorsally, widening the distance between the vertebral arch of the atlas and the spinous process of the axis. • More important, the normal linear relationship between the dorsal lamina of the atlas and the dorsal lamina of the axis becomes angular -This angular relationship between the lamina of C1 and C2 is the most reliable radiographic sign of atlantoaxial sub- luxation.

DISORDERS PRIMARILY AFFECTING THE METAPHYSIS AND PHYSIS

1. Osteochondral Dysplasias -chondrodysplasias result in disproportionate dwarfism and have been reported in breeds such as. alaskan malamutes, scottish fold cats -Distinguishing between chondrodystrophoid dogs, those that have been bred for many generations to establish a defect as a breed characteristic, and chondrodysplastic dwarfs that arise sporadically from normal parents is important *Chondrodysplasia of malamutes -inherited -often have haemolytic anaemia -Limb shortening with cranial and lateral deviation of the forelimbs and enlarged carpi are common clinical signs. *Chrondrodysplasia of norweigan elkhounds -similar to malamutes Osteochondrodysplasia of Scottish Fold Cats -This disorder is probably caused by a simple autosomal dominant trait that is expressed to some degree in cats displaying the characteristic folding of the pinna. Affected animals are shorter than normal and have difficulty supporting their weight; gait abnormalities; and a thick, inflexible tail base. Lesions are radiographically evident by 7 weeks old. -Metaphyses of the metatarsals and metacarpals are distorted, and physes are widened 2. Rickets -rare disease of young dogs and cats -abnormal mineralization due to vitamin D issues -Radiographic findings of rickets include marked widening of the physes -Flared osteochondral junctions along the ribs are called rachitic rosary and are usually easily palpated. -Diffuse osteopenia may develop 3. Hypertrophic osteodystrophy

Disorders Primarily affecting joints

1. Osteochondrosis and Osteochondrosis Dissecans

Several nonpathologic conditions can result in extension of hepatic margins beyond the costal arch.. List 3 of these

1. Overexpansion of the thorax or deep inspiration 2. Older dogs/cats (due to stretched ligaments attaching the liver to the diaphragm) -the same thing can occur in obese dogs 3. Some brachycephalic and chondrodystrophic dogs 4. Neonatal and young dogs and cats have a larger liver size compared with body size, creating the appearance of hepatomegaly without a true hepatic abnormality Because of the numerous normal variations that can cause hepatic lobe extension beyond the costal arch, rounding or blunting should also be present before hepatomegaly is concluded

A false interpretation of decreased serosal contrast often results when small bowel loops are ... (list 3)

1. Overlapping in the central abdomen 2. when loops are crowded due to a mass 3. When there is little/no gas in the lumen

3 main ddx for free gas in abdomen

1. Perforation 2. Wound to abdomen e.g. bites 3. You put it there e.g. abdominocentesis He likes to look cranioventrally, craniodorsally and anywhere there is fat (because intestine shouldnt be there) On the VD he likes to look in the retroperitoneal space

Radiographic signs of urinary bladder disease

1. Poor visualization of the UB -may be due to an empty bladder -if serosal detail is poor consider rupture, emaciated animal or free abdominal fluid from another cause 2. Displacement e.g. perineal hernia, abdominal masses 3. Change in opacity -Gas can be due to cystocentesis/catheterisation or emphysematous cystitis (more common in diabetic patients) -Calculi. If cystic calculi are identified, the remainder of the urinary tract from the kidneys to the terminus of the urethra should be examined for additional calculi. -Mineralization of the urinary bladder wall associated with neoplasia or chronic cystitis can occur but is unusual.

Differentials for a splenic mass include.. What is the most common cause of splenic lesions?

1. Primary and metastatic neoplasia 2. Hematoma 3. Nodular hyperplasia 4. Extramedullary hematopoiesis 5. Abscess Hemangiosarcoma is the most common neoplasm of the canine spleen, but splenic hematoma and hyperplastic nodules are the most common cause of splenic lesions.

Pulmonary artery enlargement without venous enlargement ddx What is the most common cause?

1. Pulmonary hypertension secondary to heartworm infection 2. Thromboembolic disease 3. Severe chronic lung disease

Pharyngolarynx What would be some indications to radiograph this area?

1. Respiratory difficulty with URT obstruction suspected 2. Stertor 3. Ptyalism 4. Gagging, and dysphagia 5. dysphonia 6. A palpable mass or a visible draining tract

Roetgen signs of pneumothorax

1. Retraction of pleural surface of lung away from pleural surface of thoracic wall, with interposed radiolucency; lung markings do not extend to thoracic wall -Seen first in lateral radiographs 2. Focal air collection around cardiac apex in lateral view -This occurs when the air is trapped against the mediastinum, most often in the dependent hemithorax 3. Appearance of dorsal displacement of the heart Seen in lateral view

Immune mediated arthritis thrall said this tends to be in the distal extremities/paws

1. Rheumatoid -Rheumatoid arthritis is a severe, progressive, erosive polyarthritis that has been reported in dogs,45 and a similar condition has been reported in cats.46 Radiographic changes usually occur in joints of the distal extremities 2. Systemic Lupus erythematosus -It has a variety of clinical manifestations, including polyarthritis, anemia, nephropathy, skin disease, pericarditis, myocarditis, and lymph- adenopathy.

Hepatomegaly List 3 potential radiographic signs of this

1. Rounding or blunting of the caudoventral liver margins 2. Significant extension beyond the costal arch 3. Caudal, and perhaps medial, displacement of the gastric axis

Thoracic Wall trauma What might we expect to see?

1. Soft tissue swelling 2. Subcutaneous emphysema 3. Tears of the intercostal musculature can result in separation of ribs and are a common sequela to bite wounds, resulting in uneven spacing between ribs 4. Rib fractures -Healing rib fractures typically exhibit round fracture margins and focal periosteal reaction followed by bridging callus. -It has been suggested that viewing VD radiographs rotated 90 degrees left or right, may improve the conspicuity of rib fractures.

The small bowel has fixed and moveable segments List the fixed segments

1. The cranial duodenal flexure is fixed along the caudal surface of the right side of the liver by the hepatoduodenal ligament in dogs. 2. The initial portion of the ascending duodenum is attached by the duodenocolic ligament

There are three openings through the diaphragm What are they?

1. The dorsally located aortic hiatus encloses the aorta, azygos and hemiazygos veins, and the lumbar cistern of the thoracic duct 2. the centrally located esophageal hiatus encloses the esophagus and vagus nerve trunks; 3. The caudal vena cava foramen is located at the junction of the muscular and tendinous portions of the diaphragm.

What about how the other abdominal organs look in GDV?

1. The enlarged stomach pushes the other organs caudally resulting in crowing 2. The spleen is also often malpositioned in patients with gastric volvulus, and may be compromised because of impaired circulation The greater the gastric distention, the less likely the spleen is to be visualized radiographically because of crowding. 3. +/- Reflex paralytic ileus of the small intestine 4. +/- esophageal dilation 5. +/- a reduced size of the caudal vena cava and microcardia and small pulmonary vessels associated with shock.

Radiographic signs of OA/DJD -what order do they come in -focus on the stifle

1. The first change is synovitits resulting in increased joint fluid 2. Focal articular degradation is second. the joint space may be wider during this stage 3. Osteophytes -When grading stifle DJD evaluating changes in number and size of periarticular osteophytes is more reliable than evaluating subchondral sclerosis, intraarticular mineralization, or synovial effusion, but signs of synovial effusion and compression of the infrapatellar fat pad are identifiable radiographic features that often accompany stifle instability. *formation can start as early as 3 days after a cruciate ligament rupture Proximal and distal ends of the trochlear ridges are the earliest sites of osteophyte formation in the stifle. At a later stage osteophytes develop on the lateral and medial femoral condylar surfaces and tibial condyles, and the patella.

What are the ligaments attaching to the stomach? (name 3)

1. The greater omentum -this is a double folded structure which extends to the urinary bladder -The superficial aspect of the greater omentum originates from the greater curvature of the stomach (this is how warren knew you weren't at the stomach during the pexy! it was covered in omentum) 2. The gastrosplenic ligament -part of the greater omentum -Attaches to the greater curvature o 3. The lesser omentum -small -extends from the liver to lesser curvature of the stomach and the cranial part of the duiodenum Includes the hetpatogastric ligament (this connects the liver with the lesser curvature of the stomach)

Of all of the structures in the mediastinum, which ones can be seen radiographically in a normal animal? (list 5)

1. The oesophagus 2. The trachea 3. The heart 4. Caudal vena cava and aorta 5. The thymus (in young animals)

Elbow dysplasia This refers to a triad of conditions including.. Extremely common problem in large breed dogs He said elbow dysplasia/problems is the most common joint related cause of FL lameness in dogs. can really occur in any breed. he also said sclerosis he finds hard to call on elbow dysplasia - there should be cortex by the notch but incresed whiteness from this is remodelling

1. Ununited anconeal process 2. osteochondrosis of the distomedial aspect of the humeral trochlea 3. Fragmented medial coronoid process of the ulna Although severe incongruity can be seen radiographically, computed tomography (CT) of the elbow seems to be more sensitive One, two, or all three of the primary lesions may be present in the same animal, and both elbow joints are commonly affected.

DISEASES OF THE URETHRA

1. Urethral calculi -In male dogs, calculi commonly occur at regions of luminal narrowing or restriction: the ischial arch and base of the os penis. -In male cats with urethral obstruction secondary to sandy mineral calculi, a mineral plug may be seen in the penile urethra 2. Urethral neoplasia and Inflammation -mass lesions caused by neoplasia or inflammation are generally indistinguishable *TCC's and prostatic carcinomas can extend from the bladder/prostate into the urethra *Granulomatous urethritis is a less common infiltrative inflammatory disease reported in female dogs 3. Urethral rupture -Typically due to pelvic trauma 4. Urethral stricture -secondary to trauma or obstruction To differentiate a stricture from inadequate urethral distention or urethral spasm, the lesion should be persistent on multiple images made during injection of contrast medium into the urethra. A stricture may be accompanied by irregular margination and luminal dilation proximal to the lesion

Differential diagnoses for pulmonary vein enlargement occurring without pulmonary arterial enlargement.. What is most common?

1. Volume or pressure overload -Mitral valve disease is the most common cause of this 2. Primary myocardial disease -DCM -HCM 3. Left atrial obstruction -mass or neoplasia at heart base -thrombosis in left atrium

Roentgen Signs of Free Pleural Fluid

1. Widened interlobar fissures that are of soft tissue opacity -Usually most conspicuous in ventrodorsal (VD) and lateral radiographs 2. Retraction of pleural surface of lung away from pleural surface of thoracic wall, with interposed soft tissue opacity -Seen first in VD radiographs 3. Increased soft tissue opacity with scalloped margins dorsal to sternum -Seen in lateral radiographs -The margin of this retrosternal opacity often appears scalloped because of adjacent, partially collapsed lung that alters the configuration of the fluid. 4.Decreased cardiac silhouette visualization -usually DV 5. Obscured diaphragmatic outline -all views 6. Blunting of costophrenic sulci -rarely seen

DISEASES OF THE PROSTATE GLAND

1. benign prostatic hyperplasia -most common prostatic disease -the prostate gland enlarges as a result of increased volume in the intercellular and ductal spaces rather than from increased intracellular volume. Solid and cystic hypertrophy are therefore different stages of the same disease, with the latter being the advanced form. -Cysts predispose to infection 2. Prostatitis -2nd most common -usually bacterial infection (can be primary or can spread from bladder or testicles) -many antibiotics do not penetrate the prostate gland readily, the prostate gland may also be a reservoir for reinfection or extension to other organs -can lead to abscesses. if ruptures can lead to peritonititis 3. Paraprostatic cysts (a cyst that can be 2ndry to advanced BPH). -Cyst no longer confined to being inside the prostate 4. Neoplasia -adenocarcinoma -often advanced at presentation with metastasis to regional lymph nodes, the pelvis, and distant sites such as the liver and lungs. -secondary infection is common for large prostatic neoplasia -can also result in cysts *These tumors are often slow to be diagnosed, unless signs of metastasis are present, because of the tendency of clinical sign of cystitis or prostatitis to overshadow those of neoplasia*

What would I expect if i saw a localised area of colonic distension?

1. impaction VS 2. localized diseases such as -mechanical obstruction -narrowed pelvic canal, mural disease -extramural tumor

Focal splenic masses Similar ddx to the liver..

1. primary and secondary neoplasia 2. nodular hyperplasia 3. hematoma (may be associated with acute or previous trauma or develop from neoplastic disease) 4. focal extramedullary hematopoiesis 4. abscess, and infarction

Abnormalities of the mediastinum are divided into three categories

1: mediastinal shift 2: mediastinal mass 3: pneumomediastinum

For a labrador size dogs, you would have to do 6 views to cover the whole of the lateral spine

1= mid cervical 2 = c7-t1 3. mid thoracic view 4. thoracolu;mbar 5. LS (ensure exposure is high enough for htis view as quite thick) 6. Coned down LS

Options for securing the uppermost leg out of the way

2nd can be better for obese dogs She prefers the right in general

He always X-rays missing teeth Always

2nd photo = dentiguous cyst

Although the overall condition of the patient must be considered, unnecessary delay of treatment is undesirable because delaying fracture stabilization for more than X hours after injury is associated with a poorer functional outcome.

48 hours

Anomalies of the vertebral column 1. Block vertebrae

= fusion of two or more adjacent vertebral bodies. - The vertebral arches may also be fused, or they may be unaffected The disc space between a block vertebra often appears radiographically as a thin radiolucent line but may not be visible at all if the fusion is complete. May increase risk of IVDD at adjacent sites

This dog was radiographed due to stifle lameness and had instability present

A TPLO surgery was planned -has joint effusion -signs of oa/djd (ventral patella osteophyte, cranial aspect of the tibia) However the periosteal reaction on the femur is not typical for what we see in patients with OA/DJD. Its active periosteal reaction The character of the trabecular pattern in the distal femur is also abnormal (small areas of bone lysis) *even if this was missed the periosteal reaction is enough to sound an alarm for an aggressive lesion

What is a bone sequestrum? Are they sterile or infected?

A bone sequestrum is a fragment of bone that has lost its blood supply and is no longer viable. -May be infectious or sterile A classic sequestrum is recognized as a sharply marginated sclerotic bone fragment (sequestrum) surrounded by or separated from the parent bone by a radiolucent zone that is surrounded by sclerotic bone (involucrum). In some instances, a draining tract (cloaca) arises from the radiolucent necrotic area surrounding the sequestrum and extends to the skin surface. Generally, less reaction occurs surrounding a sterile sequestrum; however, determining radiographically whether the sequestrum is infected is not always possible.

What about a change in shape of pulmonary vessels?

A change in shape of pulmonary vessels can also occur and is most commonly seen in dogs with heartworm disease where vessels become tortuous and may also appear to terminate abruptly, which is termed truncation or pruning

Changes in Opacity of the prostate gland

A change in the opacity of the prostate gland from its normal soft tissue opacity indicates severe or chronic disease. Areas of calcification within the gland are a sign either of longstanding prostatitis or of neoplasia.1 Wispy or indistinct calcification has a strong positive predictive value for neoplasia, particularly in dogs neutered at an early age. Prostate gland calcification is seen more commonly with sonography or computed tomography (CT) because of the better soft tissue contrast resolution associated with these modalities. The prostate gland does not normally communicate with any air-containing organ, so it should not contain gas. Intra- prostatic gas can be evidence of gas-forming bacterial prostatitis. Coliform or clostridial prostatitis results in severe hemorrhagic necrosis of the gland, potentially causing a generalized peritonitis and septic shock. Because of the rapidly fatal course of these infections, identification of noniatrogenic gas within the prostate gland is an unfavorable prognostic sign. Even if the patient survives, severe, permanent scarring of the prostate gland is likely. Sterility and urinary retention or incontinence may become long-term sequelae to such scarring. Rarely, the prostate gland may contain air because of reflux from the urinary bladder during a negative- or double-contrast cystogram.

What causes nutritional secondary hyperprathyroidism?

A diet that is calcium deficient on ca:p imbalanced Calcium is resorbed from the bone causing osteomalacia. Changes are generally diffuse Radiographically it appears as thin cortices and reduced opacity of bones A loss of definition of the normally dense dental lamina that surrounds the teeth may also occur Spinal deformity and pathologic folding fractures of the appendicular and the axial skeleton are common.

What is this?.....

A dog with mechanical jejunal obstruction caused by a cloth foreign body. There are multiple small intestinal segments that are abnormally dilated. The configuration of the dilated loops indicates that they cannot all be colon. There are two populations of small bowel: large segments and normal segments. This dog has less intraluminal fluid than most dogs with mechanical obstruction

Surgery went ahead as it wasnt detected

A later biopsy showed an osteogenic sarcoma

Joint displacement or incongruency

A luxated coxofemoral joint is a good example of this ACL injuries and elbow incongruency may be difficult to see radiographically

Testicle -Assessment on radiographs not very useful unless intra-abdominal neoplasia from a retained testicle

A thin hyperechoic line surrounds the testicle peripherally, representing the tunica albuginea and parietal and visceral tunics The mediastinum testes, a fibrous extension of the tunica albuginea that extends along the long axis of the testis, is present in the center of the normal testicle.

What does the lumen on U/S appear as if theres no fluid or gas?

A thin, hyperechoic line represents the lumen

U/S of the prostate gland (make sure you also scan the bladder and testicles)

A very small normal gland, such as seen in a neutered dog, may not be seen occasionally, but an abnormal prostate gland is usually visible cranial to the pubis The prostate gland is imaged most easily from the right side of the os penis with the dog in dorsal recumbency. The normal prostate gland is uniformly echogenic with an echogenicity similar to that of surrounding fat. However, the echotexture of the prostate gland is different than that of fat because the prostate gland has a homogenous, medium-to-fine texture, whereas fat is more coarsely echotextured. The urethra is usually seen as a small echolucency in the center of the gland surrounded by a narrow band of slightly hyperechoic tissue. Although the position of the urethra can usually be ascertained sonographically, involvement of the urethra must be confirmed by urethrography.

What do i think this nodule is? Why?

A, Close-up of the cos- tochondral region of a dog where there is an obvious circular opacity (white arrow) that could be confused with a lung nodule. Note, however, that the nodular opacity is at the dorsal end of a costal cartilage (black arrow). B, In the ventrodorsal (VD) view, the nodular opacity (white arrow) is also adjacent to the end of a rib (black arrow). The proximity of this nodular opacity to the osseous structures of the thoracic wall detracts from it being pulmonary and supports a focal mineralized enlarge- ment of the costal cartilage.

Pulmonary hyperinflation

A: Increased distance between heart and diaphragm Diaphragm is flatter then normal In B, there are multiple, relatively sharp projections from the diaphragm (black arrows) that represent the costal attachment sites. The attachment sites are visible because the hyperinflated lung is pushing the diaphragm caudally, leading to tension at the point where the diaphragm attaches to the ribs.

U/S image 1

A: Normal liver with moderately enlarged gallbladder with anechoic bile B: Normal liver and smaller GB (the wall of the gallbladder should not be easily seen as it is so thin) C: Longitudinal ultrasound image of the normal caudate liver lobe and cranial pole of the right kidney. The liver is isoechoic to the renal cortex. D: Longitudinal ultrasound image of the normal left liver and proximal portion of the spleen. The liver is hypoechoic to the spleen.

Variations of normal

A: The caudal one-third of the esophagus is visible as a soft tissue band between the aorta and caudal vena cava (white arrows). This finding is usually not present on right lateral radiographs of normal dogs. B: Small amount of gas in the esophagus just cranial to the tracheal bifurcation Tracheal stripe sign present C: Left lateral radiograph of an anesthetized dog. The endotracheal tube is visible (black arrow). There is generalized megaesophagus (white arrows) because of the anesthesia. The enlarged esophagus is causing ventral displacement of the intrathoracic trachea. Radiographically, this cannot be distinguished from pathologic megaesophagus.

Same Q as above

A: VD B: DV -the diaphragm is displaced cranially where it contacts the heart and pushes it into the left hemithorax. The cardiac silhouette is also smaller and more round, because it is more upright in the thoracic cavity due to the displacement. The overall size of the thoracic cavity is reduced in the DV radiograph.

Positioning webinar Where do I centre the light beam?

At the level of the last rib works for most patients (dogs) For cats 2cm behind the last rib *sometimes putting a sandbag between the legs on lateral will help with the position *Ideally take the image at the end of expiration (there is often a pause here)

Thoracic Wall

Abnormalities of this are often overlooked

Think twice about..

Acral lick granulomas =o

Chronic Pyloric Obstruction

Acute causes include 1. GDV 2. Foreign body Chronic causes include 1. Hypertrophic pyloric stenosis 2. pylorospasm 3. inflammation or fibrosis 4. neoplasia 5. mucosal antral hypertrophy. It should also be remembered that disease of the pancreas or proximal duodenum can lead to an outflow obstruction of the stomach, which might present similar to disease occurring at the pylorus itself. Chronic obstructions tend to have more fluid present (as opposed to gas)

How can I tell if the spleen is large on U/S?

Again size is subjective and has no absoulute size limits in dogs. In cats the height should be approximately 7-8mm in the transverse plane -The spleen may extend caudally or more completely cover the ventral abdomen. -Splenic borders become rounded or blunted, or appear to bulge from the capsule, compared with the normal sharp, linear appearance (splenic margins should normally be linear and smooth)

Pneumothorax

Air can enter the pleural space from the outside or from the lung or mediastinum In general, pneumothorax will be more conspicuous in lateral radiographs than in VD or DV radiographs; this is the opposite of pleural fluid where fluid is often first seen in the VD view Air-containing interlobar fissures are almost never seen with pneumothorax, because air does dissect between lung lobes as fluid usually does In most animals, pneumothorax is bilateral, and this relates either to a bilateral source of pleural air or to movement of air through the mediastinum. When unilateral pneumothorax was induced in 24 dogs, bilateral pneumothorax was observed immediately after air instillation in 22 dogs, indicating rapid movement of air through fenestrations in the mediastinum.6 Unilateral pneumothorax, however, can occur for the same reasons as for unilateral pleural fluid.

DV skull

Also an option She prefers VD though

What is the most common primary bone tumour of cats?

Also osteosarcoma Less common in cats Mean age at time of diagnosis is approximately 10 years HL's most commonly affected than FL's

What is the lobar sign?

An abrupt change in opacity when a diseased (opaque) lung lobe meets a normal lung lobe So L image - if the X-ray hits that boundary head on, it will create a very sharp image On the R side, it has not hit it head on so you get a blurred demarcation between normal and diseased To correctly identify a lobar sign, it is necessary to know where normal lung borders are located. If a lobar sign is seen in one view, it may not be detected in other views because a lobar sign is only visible when the junction between the affected lobe and the adjacent normal lobe is struck tangentially (i.e., in a parallel fashion) by the x-ray beam *we also will not see a lobar sign if the disease doesn't extend to the periphery of the lobe

What is a gall bladder mucocele? Do they occur in cats?

An accumulation of nondependent sludge, semisolid mucus, and inspissated bile, creating an intraluminal centralized echogenicity with peripheral striations. This creates a stellate appearance Gallbladder mucoceles have been associated with a 50% incidence of loss of gallbladder wall integrity and/or acute rupture (so sampling is discouraged in patients) Dogs diagnosed with gallbladder mucocele are more likely to have hyperadrenocorticism GB mucoceles are rare in cats as they have fewer mucus secreting glands

2. Periosteal Reaction

An active periosteal reaction is a feature of many aggressive bone lesions and is one where the margin of the periosteal reaction is irregular, not smooth. The presence of an irregular margin is the clue that the periosteal reaction is active. As might be expected, a nonaggressive periosteal reaction is characterized by a smooth edge to the periosteal new bone growth. The finding of a smooth periosteal reaction does not mean that the lesion is not aggressive, because there may be another finding that makes the lesion aggressive. Thus, a lesion with a smooth periosteal reaction but an indistinct transition zone will still be aggressive

Filling the urinary bladder iatrogenically How many mL per kg?

An approximation of 10 mL, or a range of 3.5 to 13.1 mL of contrast medium per kilogram body weight, may be used

Entheses and Enthesophytes Define both of these

An enthesis is the point of insertion of a tendon, ligament, joint capsule, or fascia to bone. Enthesitis is inflammation of the site of tendon or ligament attachment to bone. An enthesophyte is a bony spondylopathy that develops at an enthesis -enthesophytes, osteophytes, and ankylosing spondylopathy appear radiographically similar *knowing common ligament areas makes it easier to distinguish Ones to possibly know -gastrocnemius -biceps tendon

RIB TUMORS What is the extrapleural sign?

An extrapleural sign is characterized by an intrathoracic mass with a well- circumscribed, convex margin facing the lung. The cranial and caudal edges taper along the thoracic wall, giving the mass a broad-based appearance A thoracic wall mass that invades the thoracic cavity, regardless of etiology, may create an extrapleural sign. This helps to differentiate thoracic wall masses from pulmonary masses If a lung mass is in contact with the thoracic wall, the junction between the mass and the thoracic wall forms an angle of 90 degrees or less Rib metastases are often overlooked on survey radiographs, especially when the radiographs were acquired for evaluation of the lung for metastasis.

1. Mediastinal Shift What is the most common cause?

An ipsilateral mediastinal shift occurs as a result of a unilateral decrease in lung volume Whereas a contralateral mediastinal shift occurs as a result of a unilateral increase in lung volume, the presence of an intrathoracic mass, or unilateral increased pleural pressure. Displacement of the heart to the left or right is the most reliable sign of a mediastinal shift Suboptimal patient positioning with deviation of the sternum to the right or left can create the false impression of a mediastinal shift Reduced ventilation or prolonged lateral recumbency causing atelectasis is the most common cause of a mediastinal shift

What is anatomic reduction? When is this critical?

Anatomic reduction with a narrow facture gap improves the chance of direct or rapid indirect healing. Large fracture gaps or missing bone fragments require more and larger callus formation and a longer time for bridging of the fracture. In addition, anatomic reduction allows the apposition of the bone fragments to enhance the stability of the fracture. Positioning of fracture ends should have at least 50% contact to expect healing of the fracture. However, fracture healing is more likely with anatomic reduction. Anatomic reduction is critical with articular fractures to prevent long-term cartilage damage and degenerative changes from abnormal pressure distribution.

Angular limb deformities What joint is most susceptible?

Angular limb deformities develop after trauma to open physes. A Salter-Harris type fracture in an immature subject may cause premature closure of part or all of a growth plate, causing cessation of growth in that region of the bone. The most common site for this complication is premature closure of the distal ulnar physis in the dog.

A hyperechoic medullary rim parallel to the corticomedullary junction is observed commonly. Why?

Associated with many diseases It can be seen with mineralization, necrosis, and hemorrhage e.g. acute tubular necrosis, leptospirosis, pyogranulomatous vasculitis in cats with feline infectious peritonitis and in hypercalcemic nephropathy. However, a corticomedullary rim is a nonspecific finding that is also seen commonly in clinically normal dogs and cats.

Where does the rectum start?

At beginning at the pelvic inlet and ending at the anal canal.

U/S of small intestinal FB's

Appearance varies depending on the material of the FB With more complete obstruction, the foreign object may be associated with accumulation of fluid in the bowel cranial to the obstruction. In vomiting dogs, ultrasound findings of a jejunal serosa-to-serosa measurement of more than 1.5 cm, with normal wall layering, and a fluid-filled or gas-filled lumen should prompt careful interrogation of the bowel for an obstructive lesion.

How much fluid do we need to see widened interlobar fissures?

Approximately 100 mL of fluid must be present in the pleural space of a medium-sized dog before widened interlobar fissures become visible radiographically. Thus, any radiographic evidence of pleural fluid signifies a relatively large fluid volume, and one that can be sampled by thoracocentesis. With moderate or pronounced pleural fluid, the number and thickness of interlobar fissures increase, and fluid also collects between the thoracic wall and the lung, resulting in lung retraction

Tracheal hypoplasia

Approximately 40% of brachycephalic dogs with signs of brachycephalic airway obstruction syndrome have tracheal hypoplasia *all brachycephalic dogs (even without respriatory difficulty) tend to have smaller tracheas too *Tracheitis from inhaling an irritant can look similar due to mucosal thickening

Altered perichondral bone opacity

Articular cartilage merges with the synovial membrane at the chondrosynovial junction. This highly vascular membrane is sensitive to inflammation. Synovial inflammation, or hypertro- phy, may result in erosion of bone adjacent to the synovium. Early inflammation causes adjacent bone to appear ragged and spiculated. Longstanding or severe synovial inflammation or hypertrophy may cause pronounced bone erosion

Lungs appear more opaque in lateral vs VD or DV. Why?

Atelectasis The dependent lung collapses when the animal is in lateral (less so in DV or VD) -This atelectasis cannot be visualized directly in a lateral radiograph because the aerated nondependent lung is superimposed on the collapsed lung -However the increased opacity of the dependent lung causes an overall increased lung opacity in lateral radiographs that is misdiagnosed commonly as disease. -the collapsed lung also causes border effacement (or silhouetting) of any soft tissue lesion in the dependent lung Overinterpreting the increased opacity occurring in lateral views due to atelectasis as lung disease is a common mistake *Sedation and GA also exacerbates atelectasis

Congestive heart failure

Backward left-sided heart failure begins when increased end-diastolic filling pressure in the left ventricle is transmitted into the left atrium and then into the pulmonary veins creating pulmonary venous hypertension. Pulmonary venous hypertension results in pulmonary veins becoming larger than the corresponding lobar artery. Pulmonary venous hypertension is not evidence of heart failure. However, as pulmonary venous pressure continues to increase, this will ultimately result in transudation of fluid from the pulmonary capillaries into the lung interstitium, first causing a hazy, unstructured interstitial pulmonary pattern (interstitial pulmonary edema), followed by alveolar edema. Cardiogenic pulmonary edema often has a dorsocaudal distribution in dogs but any distribution is possible. A perihilar distribution is also possible but this is overemphasized Some cats with left heart failure also have a component of pleural effusion in addition to pulmonary edema

Acute duodenal obstruction can be difficult to diagnose - why? What should raise suspicion for a duodenal obstruction?

Because the stomach acts as a reservoir for gas and fluid that might collect. Also, if vomiting is frequent, the accumulated fluid and gas are expelled from the stomach and duodenum. With chronic duodenal obstruction, however, gastric distention develops and can be pronounced. A moderate to large volume of fluid and gas in the stomach, with an otherwise gasless abdomen, in a vomiting patient should raise suspicion of duodenal obstruction or pyloric outflow obstruction.

VD

Black arrows = small bronchi we would not usually see White arrow - large bronchi that we would normally see (so this isnt necessarily an AIR BRONCHOGRAM *can be especially easy to over-interpret these large bronchi when are they are over the heart

Blood clots

Blood clots tend to be associated with the clinical observation of severe hematuria. Relative to normal urine, a blood clot commonly appears as a hyperechoic, nonshadowing, mobile mass.

Ventricular Septal Defect

Blood shunts from the L to the right side due to pressure • There is mild right ventricular hypertrophy from volume and pressure overload. • Pulmonary arteries and veins can be normal or mildly dilated because of a mild to moderate increase in pulmonary blood flow; enlargement is typically less than that seen with patent ductus arteriosus

Urinary Bladder Anatomy What holds it in place?

Broken down into 3 parts - the apex (cranial), body and neck. Three ligaments formed from peritoneal reflections hold the urinary bladder loosely in position. -The middle urinary bladder ligament extends along the ventral surface of the urinary bladder and two lateral ligaments extend along the lateral urinary bladder surfaces. These ligaments often contain large fat deposits. The urinary bladder is cranial to the pubis, dorsal to the rectus abdominis muscle, caudal to the small bowel and omentum, and ventral to the large bowel. In females, the body of the uterus lies between the urinary bladder and colon/ rectum.

Uncommon

Bulla will tend to have a thin wall

How can I tell a butterfly vertebrae from a compression fracture?

Butterfly vertebrae tend to occur in brachycephalic breeds (boston terriers, frenchies, pugs, bulldogs etc) There also may be multiple of them Also, hemivertebrae have a smoothly marginated cortex, whereas vertebrae affected with a compression fracture have a disrupted margin.

How can reversible constipation and obstipation be differentiated from irreversible megacolon in cats on X-rays?

By measuring the colon vs the length of L5 If the ratio exceeds 1.5 this suggests megacolon

Anatomy of c1/c2

C1 articulates cranially with the occipital condyles, forming the atlantooccipital joint, and caudally with C2, forming the atlantoaxial joint. The wings of C1 are extensive transverse processes that project laterally and serve as attachments for numerous cervical muscles. C2 has a big spinous process -It also has the dens which we worry will damage things if this joint is unstable *in the lower picture the wings have been cropped off c1 so we can see the dens C1-C2 does not have an intervertebral disc.

Bacterial abscesses can occur as focal lesions associated with the intestinal wall What are these caused by?

Can be a consequence of partial or complete foreign body perforation Abscesses associated with the small intestine may originate from a source extrinsic to the wall. This may occur because of retained surgical sponges (gossypiboma) or be caused by a pancreatic abscess.

Intussusception What are the two most common sites? What does it look like on X-rays?

Can occur anywhere along the digestive tract but the majority occur at the ileocolic or cecocolic junction. The radiographic appearance of an intussusception is influenced by the completeness of the obstruction. Distal intussusceptions can result in generalized severe dilation of the small bowel, creating the typical appearance of mechanical obstruction although many patients with an intussusception have a partial rather than a complete obstruction. The intussusceptum will occasionally create a visible soft tissue mass effect in the colon if sufficient gas is present in the intussuscipiens to provide contrast. In most patients, however, differentiating intussusception from other causes of mechanical obstruction based solely on survey radiographs is not possible. *Dogs with evidence of blood flow in the mesentery of the intussuscepted bowel were more likely to have successful reduction compared with those with no evidence of flow.*

Hepatocutaneous syndrome appears like what on U/S?

Can result in a nodular appearance - should be suspected when the liver has a honeycomb appearance (hyperechoic hepatic parenchyma surrounding hypoechoic focal nodular areas) These patients have concurrent dermal lesions in the footpads and mucocutaneous junctions. A biopsy is critical in making the diagnosis.

Normal positioning and shape of the kidneys

Canine kidneys are oval The cranial pole of the right kidney is often poorly visible, because it abuts the caudate lobe of the liver. The right kidney is usually located at the level of the thirteenth rib. The left kidney is located more caudally, at the level of L1 to L3, and is visible more consistently R tends to be more dorsal than L

Metastatic bone cancer What cancer is most common to do this? From what location? (list 2 in dogs)

Carcinomas are more common then sarcomas -In dogs, mammary and lung cancers are a common source of bone metastasis Lesions can be either appendicular or axial The hematogenous origin suggests that a meta- physeal distribution would be most common, but diaphyseal lesions are also common.

Rib fractures in cats??

Cats with diseases that cause prolonged respiratory effort or coughing, metabolic diseases, or certain neoplasms are at increased risk of spontaneous nontraumatic rib fractures. In the population of cats evaluated for spontaneous rib fracture, the majority had respiratory disease, and the remaining cats had chronic renal disease or tumors, such as myeloma.

Oesophagitis What can cause this? Do we see it on X-rays?

Causes: Infection, corrosive or hot substances, v+, reflux, megaoesophagus or Fb's Survey X-rays are usually unremarkable

Ununited anconeal process (united is a silly term - its more likely a fracture)

Certain breeds have a separate center of ossification at the anconeal process (e.g. labs, GSD's) -we used to think the separate centre of ossification didn't unite and this was the cause but its actually more likely to be fracturing due to in-congruency The anconeal process should be fused normally to the olecranon of the ulna by 150 days of age (5 months) Breeds most at risk: Bernese mountain dogs, rotties, mastiffs, st bernards

Cervical spondylomyelopathy aka wobblers

Cervical spondylomyelopathy is also best considered a syndrome rather than a specific entity because it encompasses a variety of pathologic changes that are not seen in every affected animal. Cervical spondylomyelopathy is common in young Great Danes and mature Doberman pinschers, but there are many other large breeds that can be affected X-ray = narrowed cranial vertebral canal (black arrows)

What is one of the more common causes of biliary obstruction in cats?

Choledocholiths located in the bile ducts This can also result in cholangiohepatitis

CKD on U/S

Chronic tubulointerstitial inflammation and fibrosis is the predominant histopathologic finding in chronic kidney disease, regardless of the underlying cause. This results in poor corticomedullary definition caused by cortical and medullary hyperechogenicity.

What is a codmans triangle? What is it pathogomonic for?

Codmans traignle = A traignle of reactive subperiosteal new bone Not pathogomonic for anything though so don't get confused!

What is happening in A, B, C?

Colonic volvulus The cecum should normally be in the R lateral abdomen, its in the left! (should also normally be ventral) The large comma-shaped or C-shaped distended bowel segment in the cranial abdomen is typical of a colon torsion. Also, the cecum (C) is located dorsally and on the left, and the transverse colon (T) is in the mid-abdomen

NORMAL RADIOGRAPHIC ANATOMY What is the large intestine composed of? What is the cecum?

Composed of the Cecum, colon, rectum, and anal canal

Displacement With Rupture or Hernia of the Diaphragm

Cranial displacement of the stomach may occur secondary to herniation of the diaphragm. Even if the stomach hasn't gone through the hernia - if the liver has it will displace cranially *If the stomach goes through the diaphragm this is URGENT (it fills with air) Hernias can be 1. Traumatic 2. Hiatal Hernia -can be 3. Peritoneopericardial diaphragmatic hernias

Anatomy of the liver What does it sit between? Which part of the liver sits out of the coastal arch?

Cranially: Diaphragm Caudally: stomach, right kidney, and cranial portion of the duodenum The liver is nearly entirely within the costal arch, with the caudal ventral border, composed of the left lateral liver lobe in the dog, extending just slightly beyond the costal arch In dogs with a deep thoracic cavity, the liver lies more completely within the costal arch, whereas greater caudal hepatic extension is present in dogs with shallow, wide thoracic conformation. The caudoventral hepatic margin protruding slightly from the costal arch should be relatively sharply marginated and triangular. It may protrude farther caudally in right lateral recumbent views, where it may merge with the spleen, blurring exact definition. Abundant falciform fat, especially in cats, can result in dorsal displacement of the ventral aspect of the liver on lateral views. In VD the liver is distributed symmetrically in dogs, but a larger portion is often right sided in cats The gallbladder (which sits to the right of midline) usually can't be seen as it silhouettes with the liver tissue

Cranioventral Mediastinal Masses

Cranioventral Mediastinal Masses -Mild enlargement of the sternal lymphocenter is perhaps the smallest detectable cranioventral mediastinal mass (this is dorsal to the 2nd and 3rd sternebra) *One might assume that sternal lymph node enlargement is a sign of intrathoracic disease, but enlargement of the sternal lymph node is often secondary to abdominal disease, such as abdominal fluid, peritonitis or peritoneal tumor seeding -A mediastinal cyst, more common in cats than in dogs, is another cause of a relatively small cranioventral mediastinal mass *usually an incidental finding With other cranioventral mediastinal masses, which are typically larger than sternal lymphomegaly or a mediastinal cyst, there will usually be opacification of the entire cranioventral mediastinum and border effacement of the cranial margin of the heart in lateral views. In VD or DV views, the cranial mediastinum will appear wide, and there will be border effacement of the cranial margin of the heart. The extent of these changes depends on the size of the mass. The trachea may or may not be displaced dorsally, again depending on the size of the mass -enlarged cranial mediastinal lymph nodes are a common cause of a cranioventral mediastinal mass (they do not enlarge secondary to abdominal disease) The thymus is another common origin of a cranioventral mediastinal mass. The thymus should have involuted and be inconspicuous in most dogs by approximately 1 year of age The normal thymus can be seen in young dogs as a triangular opacity in the cranioventral mediastinal reflection in VD or DV views

Cryptococcus neoformans

Cryptococcus neoformans, a fungal infection more commonly seen in cats, can infect the nasal passages, but generally causes a nondestructive hyperplastic rhinitis Sinonasal fungal disease reported in cats include aspergillosis, cryptococcosis, and hyalohyphomycosis, and clinical signs, age, and CT features can overlap with those found with sinonasal neoplasia

Cystic Endometrial Hyperplasia and Pyometra What phase of the cycle does this occur in?

Cystic endometrial hyperplasia occurs as a result of an abnormal response of the endometrium to progesterone during the luteal phase (diestrus) of the cycle. Fluid accumulates in the endometrial glands and lumen of the uterus, and pyometra results if bacteria are present

2. Renal Cysts

Cysts are usually located at the corticomedullary junction. Solitary cysts can occur in any feline and canine breed and are not clinically significant if the renal architecture is otherwise normal. Small cortical cysts are observed commonly in conjunction with chronic degenerative renal disease

Focal hepatic masses on U/S What can U/S not differentiate between? What is it great for?

Cysts, abscesses, primary or metastatic neoplasia, hematomas, granulomas, nodular hyperplasia, and focal extramedullary hematopoiesis can all produce focal hepatic disease and may be difficult to differentiate on the basis of ultrasound appearance alone. -Hepatocellular carcinoma is the most common primary tumor in the dog -However metastatic disease in the liver is the most common hepatic malignancy in the dog at 2.5 times the frequency of primary hepatic neoplasia, and most often originates from the spleen, gastrointestinal tract, and pancreas. However, ultrasound is extremely useful in differentiating 1. cystic versus solid masses 2. focal, multifocal, or diffuse distribution of masses 3. The relation of the mass to adjacent structures, such as large blood vessels, diaphragm, or gallbladder. *As in diffuse disease, there appears to be poor correlation to cytologic and histopathologic diagnosis* -A positive cytological diagnosis of neoplasia is often accurate, but a negative cytologic evaluation does not rule out neoplasia. Target lesions, which are focal masses with a hyperechoic center and hypoechoic periphery, are most commonly associated with malignancy, but they have been reported with benign disease processes

T2, T1, stir, flair

Gadolinium is used for contrast in MRI its magnetic

Mechanical obstruction List some differentials for this What are 3 factors that can affect how the obstruction looks?

DDX 1. FB 2. Extramural mass/lesion 3. Intussusception 4. Intramural mass 3 Factors 1. The completeness of the obstruction 2. the location of the obstruction in the gastrointestinal tract 3. the duration. The most consistent radiographic sign of mechanical obstruction is a variable degree of dilation of bowel loops orad to the site of obstruction A more distal obstruction leads to a greater number of distended loops. Obstructed bowel typically contains both fluid and gas unless the obstruction is quite proximal, allowing gas and fluid to reflux into the stomach. Depending on the location of a complete obstruction there may be two distinctly different sizes of bowel with the smaller and normal diameter bowel distal or aboral to the dilated bowel. More complete and longer duration obstruction results in greater bowel distention. As bowel becomes progressively more distended, the segments become crowded into a relatively smaller space, often assuming a stacked appearance

Often patterns are mixed..what to do then?

Decide which is most prominent/obvious and do your rule out ddx list from that

Answer

Decreased serosal detail and two wedge shapes in the areas he likes to look Intestinal perf! (or stomach)

Why is it important to characterise a bone lesion as aggressive vs non aggressive?

Determining whether a bone lesion is aggressive will be helpful in directing patient management. It is reasonable to observe nonaggressive bone lesions over time to determine their course. Conversely, if a feature of aggressiveness is found, the main considerations are neoplastic and infectious etiologies. In this instance, observing the lesion can jeopardize the patient. Identification of an aggressive bone lesion should prompt consideration of thoracic radiography and biologic sampling of the lesion for histopathologic and possibly microbiologic examinations.

How would a 360 degree torsion be diagnosed?

Diagnosis depends on findings at physical examination, such as the inability to pass a stomach tube, or surgery. The finding of a small caudal vena cava in the radiographic study is also suggestive of a 360 degree rotation.

Intestinal perforation

Diagnosis this can be challenging as gas is no longer trapped in the GIT tract Intestines can look deceptively normal

Diseases of the Ureters -Most ureteral diseases result in dilatation of some or all of the ureter.

Differential diagnoses for ureteral dilatation 1. obstruction (e.g., calculi, clots, strictures, masses) *most common cause -ureteral calculi are often radiopaque (may also twinkle on U/S!) 2. ectopic ureter 3. inflammation (e.g., ureteritis, pyelonephritis) 4. atony 5. and ureteral tears.

Radiographic Signs of Specific Cardiac Chamber Enlargement 1. Left Ventricle

Dilation of the left ventricle is a likely response to chronically increased preload and is often associated with cardiac failure Dilation of the left ventricle may either contribute to an overall appearance of generalized cardiomegaly or result in the elongation of the left ventricle, causing generalized tracheal elevation In the VD or DV view, the cardiac apex may appear more blunted, and the left heart border may appear to be more rounded than its normally straight appearance. The left ventricle may enlarge as a result of hypertrophy or dilation. Concentric hypertrophy, a likely response to increased afterload such as with aortic stenosis, mainly occurs at the expense of lumen volume and may lead to no enlargement or nonspecific enlargement. Eccentric hypertrophy is likely a response to increased preload, as in patent ductus arteriosus or mitral insufficiency, and can cause visible left ventricular enlargement Why increaed preload? During LV filling, the higher pressure of the LA leads to an increase in LV end-diastolic pressure (25 mmHg in this example) and LV end-diastolic volume.

Contrast the above with direct healing

Direct (primary) bone healing is healing that occurs directly between fracture fragments without a cartilaginous stage and no observable callus. Excellent anatomic reduction and alignment of the fracture fragments with rigid fixation are required. The fracture gap must be very small—no more than 150 to 300 μm.

What is discospondylitis? What is this frequently associated with?

Discospondylitis is inflammation of an intervertebral disc and its adjacent vertebral endplates. The etiology involves hematogenous spread of microorganisms from distant sites, frequently associated with genitourinary infections and occasionally paraspinal abscess or foreign body migration. Middle-aged, large-breed dogs are affected commonly, and single or multiple intervertebral discs and adjacent endplates may be involved. Can occur in cats but less common Initial radiographic features include irregular endplate lysis with extension into the vertebral body Later, there is collapse of the intervertebral disc space, sclerosis peripheral to the endplate lysis, ventral enthesophyte production, and in some instances subluxation Resolved discospondylitis may have the same appearance as spondylosis deformans Clinical features of discospondylitis can include fever, leukocytosis, paresthesia, paresis, and rarely paralysis.49-51,54,55 Meningitis is possible if the inflammatory process extends into the vertebral canal and enters the subarachnoid space.

What is hydronephrosis?

Distention of the renal pelvis and pelvic diverticula caused by urinary tract obstruction (in contrast to infection) *the veins look like that in the X-ray because they have to stretch to reach the cortex Ureteral obstruction or aberrant termination of the ureters is a primary concern if hydronephrosis is present, and a detailed investigation of the ureters should be performed (discussed later).

Dysphagia What is the definition of this?

Dysphagia = Difficulty swallowing Can be morphologic or functional Morphologic causes -Trauma -Foreign body -an oral or pharyngeal mass -regional lymphadenopathy Functional - e.g. nervous system diseases Evaluation of functional disorders of swallowing requires contrast fluoroscopy

What do i think of this?

Early GDV (confirmed with mark) He said these ones can be tricky and you can't always been 100% The pylorus tends to be a tubular structure as you can see there If the stomach was enlarged more we would see the "double bubble" but you can still say this is segmented

What are signs of bone healing? List expected signs 5-10 days post fracture 10-20 days 30 days or more

Early healing is observed as slight widening of the fracture line and early callus formation. Later healing is observed as opaque, mature callus and increasing mineral opacity within the fracture line. Bone fragments that retain sharp margins and do not participate in the callus may indicate devitalization. If a fragment fails to revascularize, it may develop into a sequestrum. Excessive callus and periosteal new bone may be seen with fracture instability, infection, and periosteal injury at the time of the fracture or during surgery (Fig. 19.22). History and clinical signs may help differentiate these possibilities. he amount of callus is related to the type of fracture, degree of reduction, and fixation.3,55 Comminuted fractures require a larger callus to achieve adequate stabilization for healing. Fractures that have large gaps either because of less- than-anatomic reduction or missing fragments will heal with a larger callus. Fractures with anatomic reduction and rigid fixation may heal with little or no visible callus. The lack of callus in some of these fractures can be differentiated from an atrophic nonunion by clinical signs, history, and serial radiographs.

What are the radiographic signs of hypertrophic osteodystrophy?

Early stage: The double physis sign A thin margin of subchondral bone sclerosis may parallel the lucent zone and is caused by collapse of necrotic trabecular bone Irregular periosteal new bone forms around the metaphysis and is usually distinct and separate from the underlying cortex in the earlier stages of the disease. Diffuse soft tissue swelling can be seen centered on the metaphyseal regions.

Example of CT of the spine

Easy to see how the vertebrae is messed up on the right image (CT)

Ectopic ureters

Ectopic ureters are congenital abnormalities of the ureteral junction with the bladder. One or both ureters may be affected. Ectopic ureters may terminate in the bladder neck, urethra (Fig. 41.37), and in rare instances in the vagina. Ectopic ureters can be normal in size but are often dilated and tortuous with associated hydronephrosis

He wasn't sure about above but had a bad feeling about it. On the above SI measured 13-14mm (so >12) Repeat rads 24 hours later

Ended up being an ear plug

Radiographic Signs of Specific Cardiac Chamber Enlargement 1. Left atrium

Enlargement of the left atrium is the most frequently encountered cardiac enlargement in the dog due to the high prevalence of myxomatous mitral valve disease Radiographic signs 1. In the lateral view, dilation of the left atrium in the dog causes a change in shape of the dorsocaudal aspect of the cardiac silhouette. Rather than curving normally toward the tracheal bifurcation, the dorsocaudal heart border tends to course more in a dorsal or dorsocaudal direction, with straightening or formation of a slight concavity on the caudal margin of the heart This shape change has been referred to as loss of the caudal cardiac waist 2. Left atrial dilation also causes dorsal displacement of the tracheal bifurcation. Dilation of the left atrium may also cause divergence of the principal bronchi in the VD or DV view 3. A massively dilated left atrium may also lead to a region of increased opacity superimposed over the cardiac silhouette in the VD or DV view that creates the appearance of a double wall. This is caused by a summation effect of the enlarged left atrium being projected on the remainder of the heart 4. Dilation of the left atrial appendage (auricle) occurs less frequently than dilation of the left atrium and, when present, appears as a focal bulge along the left cardiac border in the 2 to 3 o'clock position according to the clockface analogy An extremely enlarged left atrium can also result in lateral displacement of the left auricle, resulting in a similar appearance without the auricle actually being dilated.

What is a kissing lesion?

Erosion of the opposing cartilage

What is a classic sign for ethylene glycol toxicity?

Ethylene glycol toxicity leads to the most dramatic increase in cortical and medullary echogenicity with a hypoechoic rim at the corticomedullary junction and hypoechoic central medullary regions The increased echogenicity is attributed to deposition of calcium oxalate crystals in the kidneys.

MM

Extrahepatic biliary obstruction. A, Ultrasound image of the gallbladder (GB) and bile duct (BD) in a cat with cholangitis and biliary obstruction. The bile duct is thickened and dilated. The gallbladder wall is thickened. B, Dilated bile duct (CBD) secondary to obstruction by a choledocholith at the duodenal papilla (D) in a cat with cholangitis. C, Dilated bile duct (CBD) secondary to obstruction by a mass at the level of the duodenal papilla (D) in a dog presented for elevated liver enzymes. Lymphoma was diagnosed on cytology from a fine needle aspirate of the mass. D, Dilated bile duct (CBD) secondary to a plug of inspissated bile (P) at the level of the duodenal papilla (D) in a cat with cholangitis.

What is the black arrow pointing to?

Fat in the renal hilus Normal feline kidneys often have a fat opacity at the renal hilus

What is pneumatosis?

Gas within the gastric wall -Predicts gastric wall necrosis Prior trocharization of the stomach will complicate assessing the sig- nificance of pneumatosis or pneumoperitoneum.

Fat in the peritoneum

Fat is typically present throughout the abdomen, primarily in the falciform ligament, the greater omentum, the mesentery, and the retroperitoneal space. The greater omentum which is usually the cause of decreased radiopacity noted ventrally on abdominal radiographs.

Gastric Foreign bodies

Food and pieces of bone in the stomach are common and often incidental findings. Non opaque gastric FB's can be difficult to identify -If the foreign body does not shift dependently with gastric fluid, then a different view may help outline the foreign body with gas. Gastric foreign bodies rarely cause perforation of the gastric wall, but when sharp objects such as wooden sticks or skewers are swallowed, perforation may occur

Lymphoma and IBD in cats

Feline alimentary lymphoma is characterized by one of two patterns; a segmental mass or more diffuse thickening of the muscular layer. The mass form, found in 75% of cats with alimentary lymphosarcoma, is expressed as transmural circum- ferential thickening in the transverse plane (4 to 22 mm) with the wall layers replaced by hypoechoic or mixed echogenicity tissue. About half of cats have associated enlarge- ment of the mesenteric lymph nodes. Recognized more recently is a variant form of feline lymphoma that has preserved wall layers but thickening of the muscular layer Of 142 cats that were either normal or had inflam- matory bowel disease (IBD) or lymphoma, there was a significant correlation between a thickened muscular layer and lymphoma. Only 1 of 24 cats with IBD had muscular layer thickening compared with 30 of 62 cats with lymphoma. However, 7 of 56 normal cats also had muscular layer thickening. Regional lymphadenopathy was more common in cats with lymphoma but did not allow discrimination between IBD and lymphoma. Cats with lymphoma were older. This suggests the odds are greater for intestinal lymphoma in older (>9 years) cats with muscular layer thickening.

Hypertrophic cardiomyopathy

Feline hypertrophic cardiomyopathy is characterized by development of a hypertrophied, nondilated left ventricle in the absence of other cardiac diseases. The poor left ventricular diastolic filling leads to reduced cardiac output with secondary increased mitral valve pressure and left atrial dilation. Radiographic signs of feline hypertrophic cardiomyopathy include the following • Moderate to extreme left atrial dilation. In cats, left atrial dilation with hypertrophic cardiomyopathy can become so large that it results in the characteristic "valentine" heart shape in the VD or DV view. Left atrial dilation may be caused by poor ventricular diastolic filling as a result of the left ventricular myocardial inward hypertrophy, systolic dysfunction, or abnormal systolic anterior motion caused by left ventricular outflow obstruction. • The left ventricle does not appear enlarged because the hypertrophy is constrictive (concentric), or inward, so the myocardium thickens at the expense of the left ventricular chamber size but does not increase its exterior dimensions. • Enlarged pulmonary veins may appear in early left ventricular decompensation, but visualization of pulmonary venous enlargement is not as common in cats with mitral dysfunction as in dogs. • Pulmonary edema will develop as left-sided heart failure progresses if not controlled by medication. • Pleural effusion is a late development.

Part 2.

Fig. 36.40 Lateral (A) and ventrodorsal (VD; B) radiographs of a dog with a large mass in the left caudal lobe. The mass has caused bronchial obstruction with secondary atelectasis, which reduces the conspicuity of the margins of the mass because of border effacement. Based on radiographic signs, one could conclude that this is an alveolar pattern rather than a lung mass, because of the intensity of the lesion and the lack of distinct margins. C, Computed tomography (CT) image of the caudal thorax. The large mass in the left caudal lobe is visible. In addition, there is an alveolar pattern in the dependent portion of the lobe (white arrow) because of bronchial obstruction. This alveolar pattern makes the mass less distinct radiographically because of border effacement. In this dog, CT was necessary to distinguish between a pulmonary mass and an intense alveolar pattern.

Positioning

For lateral and VD/DV views, the thoracic limbs should be pulled cranially to remove the brachial muscles from being superimposed on the cranial aspect of the thorax

Recommended search order

First consider things like -enough and adequate views? -Positioning? -Patient BCS and masses -Adequate aeration of the lungs? The following regions can be searched in order: (1) ribs, vertebrae, and sternebrae; (2) soft tissues of the thoracic wall; (3) pleural space; (4) mediastinum; (5) heart; (6) trachea and principal bronchi ; (7) pulmonary vessels; and finally, (8) the pulmonary parenchyma

Foreign bodies What are the most common areas in the oesophagus?

Foreign bodies are most often located at 1. The thoracic inlet 2. The base of the heart 3. just cranial to the diaphragm These are sites where the esophagus is limited in its ability to distend Common radiographic features are visibility of the distinct foreign material, gas in the esophagus contrasting with the foreign body, esophageal dilation orad to the obstruction, and signs of perforation (pleural effusion or pneumomedias- tinum). Nonobstructive foreign bodies, such as fishhooks and other sharp objects, tend to lodge in the pharyngeal region

Fungal bone infections Signalment

Fungal infections cause osteomyelitis Large breed young adult dogs are typical Cats are rarely affected Fungal osteomyelitis is generally of hematogenous origin, leading to a polyostotic distribution of the appendicular and/or axial skeleton -metaphyseal lesions are common due to the rich capillary supply there Rarely fungal infections with be monostotic (so biopsies are important if you see a lesion)

Gastric Ulcerations What are the two categories gastric ulcers are placed in?

Gastric Ulcers can be 1. Benign (aka peptic gastric ulcers) -NSAID use -Dachshunds with disc prolapse have a high prevalence of gastroduodenal ulceration. -Gastric ulceration in combination with gastritis occurs frequently in working and sled dogs 2. Malignant -Gastric neoplasia -The greatest risk factor for malignant ulcers in the dog is adenocarcinoma. Ulceration is difficult to see on conventional radiographs. May be seen with barium studies (e.g. outpouchings of the lumen, round collections of barium) *gastric ulcers in dogs that are recognized on radiographs are often the result of neoplasia Gastric ulceration can sometimes be seen on U/S but sensitivity for detecting them is low.

Is this a GDV or GD? (look at picture first!)

Gastric dilation without volvulus. A, Left lateral view. Gas is present in the pyloric antrum (P, black arrows) and body (B, white arrows) of the stomach as expected. The narrowing between the body and pyloric antrum is a peristaltic contraction. B, Right lateral view. The fundus (F, white arrows) is extremely distended. There is a small amount of gas trapped in the pyloric antrum (black arrows). The distribution of gas as a function of left versus right recumbency is as expected in a normal subject, indicating that the stomach is not rotated, unless the rotation is 360 degrees, which is unusual.

IMage

Gastric volvulus. A, Left lateral view. The stomach is moderately distended with gas in the fundus (black arrows). This is easily misinterpreted as gas in the pylorus, as expected in the left lateral view. B, Right lateral view. The fluid shifts into the fundus (F), and gas outlines the pyloric portion (P) as well as the body (B). The compartmentalization (black arrows) between the pylorus and body, and the characteristic appearance of the pylorus in the dorsocranial aspect of the abdomen, indicate that the pylorus is on the left and the fundus is on the right and that there is a gastric volvulus. Note the malpositioned and slightly enlarged spleen (S). The spleen will follow the fundus because of anatomic connections.

RADIOGRAPHIC FINDINGS IN Large Bowel Disease A colon filled with homogeneous fluid without the finely dispersed gas pattern typical for formed feces is often found in patients with..

Gastroenteritis and diarrhea

Pharyngitits and laryngitis

Generalized swelling of the upper airway can be caused by edema due to respiratory distress, as is seen in brachycephalic breeds, and/or inflammatory conditions. Also think toxicity or infectious e.g. tracheitis

When can implants be removed?

Generally, fixation devices may be removed when radiographic evidence of bridging bony callus is present. Bone plate and screw removal is delayed for 6 to 12 months after surgery to allow adequate time for the primary bone healing of the fracture to remodel into dense compact bone

Geographic bone lysis

Geographic bone lysis is a large, relatively well- defined region of bone loss It has been suggested that geographic bone lysis characterizes a less aggressive bone lesion than either moth-eaten or per- meative lysis.2 This is likely because of the presence of large well-defined regions of bone loss with benign conditions, such as an osseous cyst-like lesion. However, if cortical destruction or an active periosteal reaction accompanies geographic lysis, the lesion is aggressive.

left lateral importance

Getting a left lateral to check the pylorus has been the most useful thing hes taken away from his radiology residency HE always prefers a left lateral to the right (unless he thinks its a GDV)

He would lean toward calling an obstruction on this

He cut this dog and there was indeed a small intestinal obstruction the key to take away from this case is you should measure with the X-ray system as im not that look at judging width..

Emesis to retrieve foreign material..

He did this for the above and was successful. Not a right answer for emesis vs endoscopy vs gastrotomy vs watch and weight depends on finances, hx, physical exam etc *Even if the patient is already v+ he still recommends inducing v+ with emetics if indicated as it produces a much more forceful contraction

Foreign body VIN lecture

He divides foreign body obstructions into -Pyloric outflow obstructions -Small intestinal -Linear foreign body

Bisecting angle

He thinks of it as a sun casting shadow (the x-ray unit is the sun) If the roots are too elongated, the angle is too shallow

2. Hemivertebrae

Hemivertebrae are the result of failure of the development and eventual ossification of part of a vertebra, usually the body Appearance depends on where the failure has occurred A wedge-shaped vertebra is seen on the lateral projection when the ventral aspect of the vertebral body is developed incompletely *can result in compression *need MRI to confirm or deny this A butterfly-shaped vertebra occurs when the mid-aspect of the body fails to develop. A butterfly vertebra is best seen on the ventrodorsal (VD) projection. Decreased rib spacing on the VD projection is an important clue that hemivertebrae are present A hemivertebra should not be confused with a compression fracture; their multiplicity and occurrence in a brachycephalic breed are helpful in this distinction. Also, hemivertebrae have a smoothly marginated cortex, whereas vertebrae affected with a compression fracture have a disrupted margin.

Hepatic cyst vs hepatic abscess List two differences

Hepatic abscess -often have an echogenic rim - central anechoic or hypoechoic area -may contain gas or mineralisation -may appear similar to neoplastic masses or hyperplasia Cyst -Have a more consistent appearance -Fluid-filled, anechoic structures -well-defined, thin wall *usually an incidental finding but can cause problems if too many or too large *can be associated with polycystic kidney disease

Incomplete Ossification of the Humeral Condyle

Heritable condition of spaniels (and sometimes other breeds) Increases risk of condylar fractures The incidence of incomplete humeral condylar ossification is high enough that bilateral elbow radiographs are justified in any dog with a unilateral condylar fracture. Radiographic sign The primary radiographic finding in dogs with incomplete humeral condylar ossification is a vertically oriented radiolucent line in the central region of the condyle This lucency is evident only on the craniocaudal view Concurrent fracture of the medial coronoid process may also be present! =o

The most frequently observed diaphragmatic diseases in the dog and cat are..

Hernias 1. Diaphragmatic hernia -abdominal viscera going through the diaphragm into the thorax -Types include traumatic, peritoneopericardial, hiatal, peritoneopleural, and those secondary to congenital diaphragmatic defects. -Abdominal trauma is the most common cause of diaphrag- matic hernia. A high momentary increase in abdominal pressure when the glottis is open produces a high pleuroperitoneal pressure gradient that may result in a diaphragmatic hernia -In one study, only half of the animals with a trauma-induced diaphragmatic hernia had a history of known trauma. -The organs that most frequently herniate are, in order of prevalence, the liver, small bowel, stomach, spleen, and omentum Clinical signs that may be observed with diaphragmatic hernias include dyspnea, pain, vomiting, regurgitation, muffled heart sounds, and a weak femoral pulse.

Poll5 Obstructed or not?

His feeling in this case is that -the stomach is not overly distended and the rocks appear small in the pylorus -we can see evidence of stones on the colon He would monitor and not surgerise this patient BUT no one right answer - could have considered emesis or scoping He thinks these cases are the ones where REPEAT RADIOGRAPHS 6-24 hours later are of huge value He will do this for -non obstructive FB's -unsure if obstructed -owner/patient logistics

Nasal foreign bodies

History is important -Affected dogs have an acute onset of sneezing and pawing at the nose, and they often have unilateral nasal discharge that may be purulent Radiopaque foreign bodies are obvious in radiographs. Localization of non-radiopaque foreign bodies may be suspected in radio- graphs based on the presence of inflammation and mucopurulent material, which appear as increased soft-tissue opacity.

Strictly from the perspective of roentgen signs, the diffuse type of medullary sclerosis seen with panosteitis would be characterized as aggressive due to the lack of a distinct transition zone between the normal and abnormal bone..

However, with the scenario of a young, lame, large dog, the tentative diagnosis of panosteitis is made. However, it should always be kept in mind that in patients not responding or not improving spontaneously as expected, repeat radiographs should be considered to rule out other abnormalities, such as a medullary infection.

Increased subchrondral bone opacity

In benign joint disease such as DJD, the bone opacity may be increased due to stress remodeling Increased subchondral bone opacity usually appears as a subchondral zone of increased opacity 1 to 2 mm wide.

Flexed view - how flexed??

Hyperflexed Looks She also places some foam under the carpus (this helps to counteract the lifting that happens at the elbow when you flex the joint) Try not to put the sandbag on top of the carpus because this will push the elbow joint up

Why may the prostate gland not be seen in very thin animals or if there is fluid in the bladder neck?

Identification of the prostate gland depends on contrast provided by the presence of surrounding fat A reliable sign of the vesicoprostatic junction and prostatomegaly is a triangular region of fat between the urinary bladder, prostate gland, and ventral abdominal wall

There is a grey zone in measuring the bowel diameter..

If <1.4 then cerenia + subq fluids and bye felicia He says if you need a cut off to think surgery - use 2.1 If you are using 1.6 as your cut off, you are going to have a lot of negative explores

What to do if i can only see a nodule/mass in one X-ray view?

If a nodule is seen in only one view, the patient should be examined physically for superficial structures, such as a papilloma, teat, or ectoparasite, which might have created the opacity. If no superficial structure that could be the source of the opacity is found, and neither fluoroscopy nor CT are possible, repeating the thoracic radiographs at a later date is advisable to reassess the suspected nodule for progression.

What does a smooth prostatic margin indicate versus a rough margin?

If the prostate gland has a smooth margin that is easily seen, the disease involving the gland is likely to be benign or is slowly progressing , such as benign hypertrophy and low-grade or chronic prostatitis. A rough or indistinct margin in the presence of adequate abdominal fat is more likely to be caused by an acute or aggressive process such as neoplasia or acute prostatitis. When the margin is indistinct or not discernible, the impression is that of a localized peritonitis in the caudal abdomen. Most patients with aggressive prostatic disease have some evidence of secondary inflammation affecting the surrounding tissues.

Focal Hepatomegaly What could we expect to see with this?

If we can see it depends on the degree of enlargement and lobe Focal hepatic masses usually result in distortion of the hepatic outline and are continuous with the liver in at least one projection Left hepatic masses result in displacement of the stomach and spleen dorsally and to the right Right-sided hepatic masses displace the stomach and duodenum to the left and dorsally and the small bowel caudally. The right kidney and distal extremity of the spleen may also be displaced caudally by a right-sided hepatic mass With few exceptions, masses located cranial to the ventral aspect of the stomach are hepatic in origin. Although hepatic masses classically result in caudal displacement of the stomach, a focal mass can extend caudal to the stomach -can be difficult to tell from a splenic mass

Are ring shadows and tram lines abnormal?

Important in the identification of a bronchial pattern is the understanding that the number of ring shadows and tram lines is increased over the normal allotment. A few ring shadows and tram lines can be seen in every normal radiograph because of some normal airways being projected directly end-on or side-on.

Is "perihilar" CHF common in dogs?

In 61 dogs with pulmonary edema from mitral insufficiency, only 7 (11.5%) had a perihilar distribution of edema with the remaining having either a diffuse (18%) or patchy (70.5%) distribution.28 Therefore, although dogs can have perihilar cardiogenic pulmonary edema, other distributions are more common.

pt3

In A the size of the stomach was judged to be at the upper limit of normal, containing both gas and fluid. There is also a single vertically oriented short segment of small bowel that is distended with gas, and there is a small amount of gas and granular material in the descending colon. The remainder of the bowel is gasless and of small diameter. In B there is gas in the proximal duodenum, evidence that the pylorus is patent, and the duodenum is abnormally dilated. Immediately caudal and ventral to the fluid filled pylorus is a round mottled opacity in a fluid filled dilated loop (white arrows). (D) another lateral view was obtained several hours later. They are relatively unchanged from the earlier radiographs. However, in D there is now gas in the distal duodenum outlining a soft tissue foreign body (white arrows). A focal mineral opacity is present in all views in the caudal ventral aspect of this foreign body that was subsequently identified as a corn cob.

Septic arthritis in cats

In cats, hematogenously disseminated septic arthritis may be caused by a variety of microorganisms, which include Myco- plasma gateae, Mycoplasma felis, bacterial L-form infection (Pasteurella spp.), calicivirus (transient arthritis in kittens), coronavirus (feline infectious peritonitis). Affected cats may be systemically ill

What does the arrow point to???

In cricopharyngeal chalasia, the cricopharyngeal sphincter does not maintain positive resting pressure between swallows.

Decreased subchrondral bone formation and bone cysts

In inflammatory joint disease, inflammatory exudates may cause pronounced subchondral bone loss. Infectious arthritis may extend into subchondral bone. Subchondral bone loss appears initially as a ragged margin of subchondral bone, but it may extend to cause marked destruction of bone. When bone loss affects smaller carpal and tarsal bones, these small cuboidal bones may be dramatically reduced in mass.

There are several potential pitfalls in imaging of the urethra that can result in misdiagnosis of urethral calculi. List 2

In male dogs, nipples may be superimposed upon the penis on lateral views. This can be differentiated from a calculus first by inspection of the patient for the presence of nipples adjacent to the prepuce. Coating the nipple with barium paste or another type of metallic marker and repeating the radiograph can be performed for definitive assessment. (photo A) Some male dogs have a separate center of ossification of the os penis that results in a mineral body separate from the cranial tip of the os penis. (B) This should be recognized as a normal anatomic variation and would be an unexpected location for a calculus. In some male cats, a small and faintly mineralized os penis is visible on radiographs and may be mistaken for urethrolithiasis.

So if we can't see the MCP that clearly on X-rays..how do we diagnose it?

In most instances, the radiographic diagnosis of fragmented medial coronoid process is made indirectly through recognition of secondary osteoarthritic changes that accompany the primary lesion. A neutral lateral and a craniocaudal radiograph of both elbow joints should be made. In addition, a flexed lateral radiograph facilitates visualization of new bone formation on the proximal nonarticular margin of the anconeal process. Flexing the elbow, however, induces a mild degree of rotation that can partially obscure the medial coronoid margin A cranial 25-degree lateral/caudomedial view can also be obtained to highlight the medial coronoid region and fragmented coronoid process.

Congenital Cardiovascular Lesions (much less common then the above heart diseases..) just have a brief idea 1. Patent ductus arteriosis

In patent ductus arteriosus, the ductus fails to close normally after birth. This results in an abnormal communication between the descending aorta and the main pulmonary artery. Blood shunts from the aorta to the pulmonary artery This results in pressure and volume overload of the pulmonary circulation Radiographic signs • Dilation of the proximal aspect of the descending aorta caused by turbulent blood flow • Enlargement of the main pulmonary artery from increased pressure and flow • Enlargement of the left atrium, and possibly the left auricle, from increased blood flow • Enlarged left ventricle, initially caused by dilation followed by hypertrophy • Enlarged parenchymal pulmonary arteries and veins caused by volume and pressure overload

Cardiogenic pulmonary Oedema Where does it tend to present? Is it always an alveolar pattern

In reality, cardiogenic pulmonary edema is usually dorsocaudal or patchy and is often not as intense as a pneumonic process Another misconception of cardiogenic pulmonary edema is that it always causes an alveolar pattern. This is not true, especially in cats with hypertrophic or restrictive cardiomy- opathy, and in large-breed dogs with dilated cardiomyopathy; in each of these cases, the radiographic pattern resulting from cardiogenic pulmonary edema can be that of a bronchial pattern

What are the radiographic signs of OCD lesions?

In short -Flattening or concavity of the subchrondral bone -Subadjacent sclerosis -+/- mineralized flap The main sign is flattening or concavity of the affected subchondral bone surface with surrounding subchondral bone sclerosis. -This may result in nonuniformity and apparent widening of the joint space. -When mineralized, a cartilage flap is sometimes seen within the subchondral defect, and separate osteochondral fragments (joint mice) may migrate within the joint space. -fragments may enlarge over time -non mineralized flaps cannot be seen on X-rays - Joint effusion, or joint-capsule thickening, may appear as a localized region of soft tissue swelling centered on the affected joint. -A subchondral bone defect is occasionally seen involving the articular surface opposite the primary lesion. These defects are called kissing lesions. Degenerative joint disease is a common sequel to osteochondrosis.

c6 dog, cat

In the dog and horse, the transverse processes of C6 (black arrows) are larger than on other cervical vertebrae and serve as useful anatomic landmarks. In the cat (B), the transverse processes on C6 are only minimally larger (black arrows) and not as conspicu- ous and therefore not as useful as an anatomic landmark.

Radiographic Signs of Pulmonary Arterial and Venous Changes Which later is best to view these>?

In the lung vessels and airways are arranged in an artery-bronchus-vein triad, with the bronchus always being positioned between the pulmonary artery and pulmonary vein. Veins are ventral and central The right cranial lobar pulmonary artery and vein are valuable reference vessels, because they are best seen as individual structures when the animal is in left lateral recumbency The caudal lobe pulmonary vessels are better seen in the DV view than in the VD view, because the lungs are better inflated when the dog is in sternal recumbency

What is often mistaken as an OCD lesion on the stifle?

In the stifle, the fossa for the origin of the long digital extensor muscle is sometimes mistaken for a lateral femoral condyle osteochon- drosis lesion, because it is superimposed on the dorsolateral aspect of the lateral condyle on both the lateromedial and the caudocranial views

TMJ view

In this view the dependent TM is positioned more cranial to the caudal

Joint incongruity can be seen in association with FCP - why should we cautious of this?

Incongruity can be easily overinterpreted. On the lateral view, the normal overlapping lucent lines representing the complex elbow joint margins can be confused with joint incongruity when even mild positioning obliquity is present. CT is now used routinely to diagnose fragmented medial coronoid process and is more sensitive than survey radiography for detecting the coronoid fragment

Normal renal size and structure does not rule out kidney disease What is the most common ultrasonographic abnormality observed with both acute and chronic nephropathy?

Increased echogenicity of the renal parenchyma Ultrasonographic findings associated with acute kidney injury include -renal enlargement -subcapsular or perirenal effusion - cortical hyperechogenicity. In severe or advanced disease, the medullary echogenicity increases as well, leading to reduced corticomedullary distinction. It is usually not possible to determine the cause of acute kidney injury by ultrasound, and biopsy may be needed

Radiographic signs of panosteitis

Increased opacity in the diaphysis of long bones is the main sign Smooth continuous periosteal new bone formation develops in the diaphysis of affected bones in one- third to one-half of dogs. Panosteitis. Left (A) and right (B) elbows of a 6-month-old canine mix with panosteitis. In A, there is a focal increase in medullary opacity in the proximal ulna. This nodular appearance is typical of very early panosteitis. In the right elbow of the dog in A, there is more diffuse increased medullary opacity in the ulna, which is typical of a later stage of the disease.

Fracture healing can either be 1. Direct 2. Indirect which is most common in vet med?

Indirect (secondary) bone healing is the most common type of healing observed in animals and occurs in fractures in which some movement is possible between fracture fragments because of a lack of rigid fixation. Secondary bone healing involves callus formation involving both intramembranous and endochondral ossification Endochondral ossification occurs by ossification of cartilage The initial stage of healing is characterized by hematoma formation and subsequent inflammation. Initially, the fracture gap is bridged by tissues that are more stress tolerant, with replacement of each tissue type by a more rigid type of tissue until a rigid bridge is formed between the fragments. Granulation tissue can withstand 100% stretching before failure, whereas fibrous tissue can withstand only 10% and bone only 2% deformation before failure. The initial hematoma at a fracture site is replaced by granulation tissue followed by fibrous connective tissue that is replaced by fibrocartilage and then endochondral ossification to produce a bony union. The initial bony bridging callus is woven bone that is remodeled over time to produce compact cortical bone

What is orchitis

Inflammation of the testicle -Rare - Bacteria ascending from the prostate gland or urethra through the ductus deferens is the usual cause of orchitis. -Viral orchitis has been described in the cat as an early component of noneffusive feline infectious peritonitis *Testicular torsion is an important differential diagnosis for orchitis on ultrasound examination, but differentiation can usually be made with Doppler ultrasound examination

Infarct The echogenicity of focal splenic infarction changes over time. Describe

Initially infarcts are hypoechoic and may appear as a well-demarcated round or bulging mass or simple focal enlargement of the spleen With age, infarcts become increasingly echogenic and often are demarcated sharply from the normal splenic parenchyma. With color Doppler there is a lack of blood flow in the infarcted area.

What is excretory urography?

Intravenous contrast is given to highlight the kidney and ureters Suspected trauma to the kidney or ureters, however, is still an important indication for excretory urography. In the nephrogram phase, contrast-medium arrival in the glomerular vessels and filtration into the nephron leads to uniform opacification of the renal parenchyma In the pyelogram phase, contrast medium is concentrated in renal tubules as a result of reabsorption of water and excreted into the renal pelvis with its diverticula and the ureters

Flexor enthesiopathy

It has been reported in large breed dogs and in cats as mineralization and metaplastic bone formation at the origin or myotendinous junction of the flexor carpi ulnaris muscle. Flexor enthesiopathy has been reported as a primary disease finding and as a concomitant finding in patients with elbow dysplasia with a prevalence of 6% and 34%, respectively.98 The most common clinical finding is chronic mild lameness with pain elicited on pronation of the antebrachium with the elbow and carpus in flexion. Radiographic Signs Flexor enthesiopathy is radiographically characterized by osseous bodies adjacent to the medial humeral epicondyle, a spur of enthesious new bone extending caudally from the medial humeral epicondyle and irregularity of the medial epicondyle

Vaginogram

It is important the catheter tip is in the vestibule and not be located in the vagina because vaginal rupture can occur if the balloon occludes the orifice between the vagina and vestibule. If the procedure is performed during estrus, contrast medium may pass through the cervix into the uterus.

An understanding of the anatomic relation of the large bowel to other viscera is important for the radiographic recognition of diseases of the large bowel and adjacent organs What does the ascending colon sit next to?

It lies adjacent to the descending duodenum, right lobe of the pancreas, right kidney, mesentery, and small bowel.

Splenomegaly 3 with..

Lateral abdominal radiograph of a dog with gastric volvulus. The spleen is markedly enlarged, with elongation and rounding of margins secondary to splenic torsion.

How to improve the chance of seeing dynamic tracheal collapse

Lateral radiographs made on peak inspiration and expiration can help characterize dynamic tracheal collapse Even when collapse is not identified, an undulating appearance of the tracheal wall and mild variation in lumen diameter are suggestive of chondromalacia.

Gastric Axis

Laterals: The axis of the stomach from the fundus through the body and pylorus is either perpendicular to the spine, parallel to the ribs, or somewhere between these angles -The pylorus may be superimposed over the body of the stomach (Fig. 46.2, A) or located slightly cranial to the body (seen in B) -The fundus and/or body may be difficult to see in a left lateral view because of the intraluminal fluid silhouetting with adjacent structures. VD: -The long axis of the stomach is generally perpendicular to the spine - The cardia, fundus, and body of the stomach are located to the left of midline, and the pyloric portions are located to the right of midline -The pyloric sphincter in the dog usually is located in the right cranial abdominal quadrant at approximately the level of the tenth or eleventh rib and is usually cranial to the pyloric canal.

GD or GDV?

Left (A) and right (B) lateral views of a dog with acute gastric dilatation. On the basis of these radiographic findings, the pylorus and the fundus are positioned normally. A gastric tube could not be passed into the stomach. Final diagnosis was 360-degree gastric volvulus. Tricky one ;)

What about left atrial enlargement in a cat?

Left atrial enlargement in the cat is much less conspicuous radiographically. In many cats with echocardiographically proven left atrial dilation, there is no radiographic evidence of such. In some cats, a focal concave defect will be present on the dorsocaudal aspect of the cardiac silhouette, but this is not as common as in the dog. Another change that occurs with left atrial dilation in the cat is an increase in width of the cardiac base in the VD or DV view. Cats with marked left atrial dilation can have a so-called "valentine-shaped" cardiac silhouette in the VD or DV view due to pronounced enlargement of the cardiac base region (Fig. 35.10). A valentine-shaped cardiac silhouette is often misinterpreted as evidence of biatrial enlargement, but in most cats a valentine-shaped appearance is due to pronounced left atrial dilation without enlargement of the right atrium

Dog with an amputated leg. Which side? why?

Left forelimb Lung appears more opaque on the R side due to superimposition of soft tissue muscles This could be misinterpreted as an interstitial pattern

LS

Left image: we can see air bronchograms and increased lung opacity AND we also have a sharp demarcation between the abnomral right middle lobe and the normal right caudal lobe On the VD we can see a sharp demarcation between the R cranial lung lobe and the R middle lung lobe -the circle that the arrow points to and the bronchus above and below are confirmed air bronchograms Border effacement of the heart is a common finding with an intense alveolar pattern when the abnormal lung and heart are in contact.

Cut!

Linear FB -Fragmented gas bubbles (the caudal red arrow points to this)

Linear foreign bodies What is the most common fixed site of hte linear FB in a cat? dog?

Linear foreign material that becomes trapped in the intestine usually causes both an abnormal shape and contour of the loops and an abnormal gas pattern Some portion of the linear material typically becomes fixed at an orad location, most commonly in the pylorus in dogs and under the tongue in cats. The remainder of the length passes into the small intestine. The peristaltic action of the bowel causes it to climb the linear foreign body, which results in a pleated, plicated, or bunched appearance of the affected loops. With a linear foreign body, the loops may not become markedly distended but gas commonly becomes trapped in pockets formed by the pleats. The result is an abnormal pattern of round, tapered, short-tubular, and some- times crescent- or comma-shaped gas shapes. Gas bubbles of these shapes can be referred to as having a geometric shape. This pattern may be accentuated in the left lateral view as gastric gas moves into the duodenum from the stomach. The left lateral also often allows identification of foreign material anchored in the pylorus, surrounded by gas. In the cat, the plication of the bowel can cause a clumped or bunched positioning of the bowel. The displacement of the small bowel into the middle or right side of the abdomen in the obese cat should not be misinterpreted as plication caused by a linear foreign body There are some differences between dogs and cats with regard to linear foreign objects: (1) affected dogs are usually older and have less irregularity in the gas pattern; (2) dogs are more prone to secondary intussusception; (3) dogs have more evidence of bowel trauma or bowel laceration and peritonitis, both radiographically and surgically; and (4) the probability of death as a result of linear foreign body is nearly twice as high in dogs as in cats.

Liver lobe torsion

Liver lobe torsion is variable in appearance. The abnormally positioned lobe may be hypoechoic or mixed in echogenicity. Doppler evidence of blood flow is reduced or absent in the abnormally positioned lobe

Anatomy of the oesophagus

Located left to the trachea in the throat

US@2

Longitudinal image of uterus with severe cystic endometrial hyperplasia (between arrowheads). Note the large anechoic, fluid-filled regions in the horn.

What are the radiographic signs of FCP?

Look at the attached image. So we are not really relying on seeing the fractured cornoid process itself, but secondary changes -new bone formation on the proximal (or non articular) anconeal process (most common and earliest). Very important to know this From book The main radiographic signs include 1. An abnormal contour, or poor definition, of the cranial margin of the medial coronoid process on the lateral view. -Often the margin, which is distinct in normal dogs, cannot be followed proximally to the articular surface in affected animals. 2. On the craniocaudal view, the medial margin of the medial coronoid process may appear blunted or rounded. Secondary changes include -osteophyte formation on the anconeal process (one of the first DJD signs) -New bone is also often present on the lateral epicondyle -Subchondral bone sclerosis also develops adjacent to the trochlear notch and the proximal radioulnar articulation near the lateral coronoid process. *these changes are best appreciated on lateral

Pelvis She says she never holds for these!

Look at where the red lines are! -Neck of femur to patella She wraps cellotape around really tight Check for rotation by looking at the obturator foramen Extend the view so it includes the top of the illium and the stifle joint

Lateral spine

Look for sagging! Theres often a natural dip in the neck - a foam pad corrects this

What would I worry about if i see a radiolucent area about an implant?

Loosened orthopedic devices commonly have a radiolu- cency surrounding the device within the bone. Other than motion, either of the implant or of the fragment, additional causes for radiolucency around an orthopedic implant are bone necrosis caused by high-speed drills, digital radiographic artifact, or osteomyelitis. A radio- lucent zone around a metal implant that is relatively even with a visible sclerotic margin suggests a cause other than infection. Radiolucency surrounding a metal implant that is uneven with ill-defined margins is more likely infectious.55

Lung Patterns List the 3

Lung disease is broken down into the compartment it involves -Bronchial -Alveolar -Interstitial Certain patterns are associated with certain diseases The distribution of the pattern is also important

Lung lobe torsion What is this?

Lung lobe torsion is characterized by axial rotation of a lung around its bronchus leading to bronchial and pulmonary vein obstruction. Radiographic features occurring with lung lobe torsion include (1) enlargement of the affected lobe; (2) concurrent pleural effusion; (3) an abnormal shape and/ or position of the affected lobe; and (4) truncation, blunting, and/or displacement of the bronchus supplying the affected lobe Small dispersed air bubbles, termed vesicular emphysema, may also be seen occasionally *pugs are overrepresented

MRI

MRI works by magnetism -no moving parts -no radiation concern However the magnetism does create safety concerns MRI images hydrogen protons which are attached to water (they act like magnets)..quite complicated. most lesions have increased water - oedema, inflammation etc

Antebrachium 2 views

Make sure youve got the joint above and below

Intra-articular gas What causes it?

Many causes ranging from infection, to traction, to iatrogenic to OA/DJD

Small Intestines What are Roentgen signs for the small intestine?

Margination: serosal surface definition Size: diameter of lumen and/or serosa-to-serosa Position: location within abdominal cavity Shape: contour of bowel loops Radiopacity: lumen contents and bowel wall Architecture: mucosa/bowel wall smoothness Motility: intermittent narrowing of contractions *last two are better assessed in U/S

Microhepatia What are the two most common causse?

Marked microhepatia results in cranial displacement of the stomach and decreased distance between the diaphragm and gastric lumen 1. Hepatic cirrhosis 2. Portosystemic shunt (results in hepatic atrophy)

The presence of a mass effect (increased soft tissue in the nasal cavity) along with bone destruction is a hallmark sign of nasal neoplasia What about a mass effect with no bone destruction or vice versa?

Mass effect with no bone destruction = more suggestive of infection Bone destruction with no mass effect = think aspergillosis

Talus OCD.

Medial trochlea is most common Red arrows = small fragment Occasionally the only evidence of OCD of the talus will be this slight peripheral irregularity Common in lab retrievers

2. Mediastinal masses

Mediastinal masses are common, and the specific etiology is rarely determined radiographically. Mediastinal masses are rarely completely outlined by gas, as a lung mass would be, because the mediastinal mass will be in contact with other soft tissue structures in the mediastinum.

Elbow views Standard views. - list the 3

Mediolateral flexed Mediolateral neutral Cranial caudal

Articular soft tissue mineralization

Mineralization may occur within the joint capsule, synovial membrane, or synovial fluid as a consequence of chronic joint disease.

Meniscal ossicles in cats What is this? caused by?

Mineralization of the meniscus in the stifle -common even in cats without lameness -does seem to correlate with cartilage damage though so suspect oa/djd

Is it OK to do a dogocram/catogram?

More acceptable now due to post processing She feels its acceptable *when sending images to a radiologist of abdomen, include when last ate (helpful to assess delayed gastric emptying), clear signalment and a concise hx.

Joint mice examples

Most L image -last osteophyte on the caudal aspect of the humeral head -large joint mouse (this is a common spot for these as this is where the shoulder joint capsule ends). its called the ventral pouch of the shoulder joint *joint mice in this location are not of great clinical significance Middle image and R image (both same leg) -two joint mouse! -one in the ventral pouch of the shoulder joint -another one medial to the proximal humerus! so this one is actually located in the tendon sheath of the biceps muscle. So this little guy has migrated quite a way and could cause irritation to the biceps tendon and bicipital tenosynovitits *osteophytes on the cranial and caudal aspects of the glenoid and caudal humeral head (so has DJD)

Interstitial Pattern These are broken down into structured (presence of a nodule or mass) and unstructured causes Give examples of structured interstitial disease The interstitium is the infrastructure for distribution of blood vessels, lymphatics, and bronchi throughout the lung.

Most cases of structured interstitial patterns will be non cavitary Fake out means a nipple shadows, pulmonary vessels overlapping a rib.. Non cavitary 1. Fake out 2. Tumour 4. Inflammatory Cavitary (contains gas) 1. Bulla 2. Lung abscess 3. Necrotic tumour 4. Parasitic In the photo we would not even consider alveolar disease as you can see its sharply marginated

Cystic ovarian disease

Most cats and dogs with ovarian cysts have no clinical signs or reproductive abnormalities however even small cysts have the potential to change endocrine activity (think prolonged estrus)

Moth eaten and permeative

Moth eaten lysis is characterized by multiple medium to small lytic foci and permeative lysis by smaller, or pinpoint, lytic foci

What does the diaphragm consist of? What are some attachment sites?

Movement of the diaphragm provides approximately 75% of the change in intrathoracic volume during quiet respiration, with the intercostal muscles providing the remainder. The diaphragm consists of a tendinous center and three thin peripheral muscles -The pars lumbalis consists of the right and left crura, which attach to the cranial ventral border of L4 and the body of L3 (this can can cause the appearance of lysis) -The pars costalis attaches in an oblique direction to the thirteenth through eighth ribs - the pars sternalis attaches to the xiphoid cartilage. Lymph vessels from the abdomen penetrate the diaphragm and drain into the thoracic lymph nodes and vessels. Thus inflammatory or neoplastic abdominal disease may spread to the mediastinum and pleural space. Lymph flow is unidirectional with the final destination being the thoracic trunks

Multiple cartilaginous exostosis

Multiple cartilaginous exostosis is a benign proliferative disease of bone and cartilage. -suspected to be heritable Any bone that develops by endochondral ossification may be affected, and simultaneous involvement in multiple bones is common Growth usually ceases once the animal has reached maturity, resulting in nonpainful bony protuberances throughout the skeleton. The bone lesions are of no clinical significance unless they arise in an area in which function could be compromised, such as the vertebral canal and the trachea

The heart can look quite different depending on the breed

Muscular dogs or those with a barrel-shaped thorax have a cardiac silhouette that looks large. Conversely, the normal cardiac silhouette in breeds with a laterally compressed but deep thoracic cavity, such as greyhounds and collies, can look abnormally small *If any suspicion of a cardiac abnormality exists, because of either radiographic appearance or clinical or historical information, then echocardiography is indicated In large-breed dogs, the cardiac silhouette will be magnified in VD views when compared to DV views due to its increased distance from the imaging plate

Myelolipoma

Myelolipomas, seen as focal hyperechoic nodules, some with acoustic shadowing, are present along the dorsal border. Myelolipomas are fatty, hyperechoic nodules occasionally seen in the normal spleen, especially along the peripheral margin or adjacent to vessels Splenic myelolipomas are benign incidental findings but can be quite large.

Naming Radiographic Projections

Name from point-of-entrance to point-of-exit (of the primary X-ray beam)

What is this??.

Name the white arrow

Aspergillosis

Nasal aspergillosis is a destructive rhinitis that also typically involves the paranasal sinuses of the dog; it affects younger (younger than 4 years old), nonbrachycephalic dogs more frequently than other types.152 Aspergillus species (primarily Aspergillus fumigatus) are common environmental saprophytic fungal organisms. The most common radiographic appearance of nasal aspergillosis includes lysis of conchae with punctate lucencies of bone Frontal sinus involvement is variable Bony nasal septum erosion or deviation is uncommon except in advanced disease. Invasion into surrounding bone is more likely to be neoplasia then aspergillosis Diagnoses of fungal disease requires direct visualization of fungal plaques by endoscopy or fungal elements found by cytology or histopathology

Radiographic features of bone infection and tumours

Nearly all infections and neoplasia have aggressive features A definitive distinction between neoplastic and infectious bone lesions is impossible by radiographic means. However we can get clues with radiographic features, location, signalment, history and lab findings.

so use it but not alone..

Need to also base it on -history -physical exam findings (abdominal pain significantly increases his suspicion of FB) -again with v+ through cerenia He again said its not wrong to have a negative explore

Neoplasia of the testicle

Neoplasia may appear as a nodule or mass, which may or may not alter the shape of the testicular margin, displace the mediastinum testes, or make identification of the epididymis difficult *however often you can palpate that the testicle is enlarged Cystic hyperplasia/squamous metaplasia of the prostate gland commonly accompanies functional Sertoli cell tumors.

IN vet, what do we use MRI for?

Neuroimaging is the main one! Musculoskeletal its also useful but uncommon.

Can we tell neoplasia from infection based on X-rays?

No History, signalment, clinical signs and lesion distribution can give hints but you cannot say definitively

Should the diameter of the small intestines vary in the cat and dog? What is the typical diameter of a dog intestine? Cat?

No - they should be of similar diameter. Contractions will cause small changes in size. Dog: Less than 1.6 times the height of the L5 vertebral body at its narrowest point Cats: Not exceeding a diameter of 12 mm when gas filled. Should have a maximum SI diameter of less then 2 L2 vertebral endplates In a series of cats, when the maximum small intestinal diameter to L2 vertebral endplate height was >2.0, gastrointestinal disease was present, and at a ratio of >2.5, the most likely abnormality was intestinal obstruction.

What is the most common abnormality of the spleen detected on U/S?

Nodular hyperplasia -has a similar appearance to hyperplasia in the liver -The splenic border may simply be smoothly irregular or isoechoic; hypoechoic or hyperechoic nodules may be present. -Hyperplastic nodules can be quite large and complex. *Extramedullary hematopoiesis can appear as hypoechoic, hyperechoic, or mixed echogenicity nodules and/or masses

Distribution Where would we expect to see an alveolar pattern for 1. Pneumonia 2. CHF 3. Haemorrhage 4. NCPE 5. Atelectasis

Non cardiogenic pulmonary oedema can be really variable though Other even less common causes are.. -Thromboembolism -Allergic disease (eosinophilic) -ARDS All of these are variable in distribution

Radiographic signs of joint disease in dogs and cats

Non specific Variable depending on where in the disease course

Normal radiography of the colon How can feces be told apart from small intestinal loops?

Normal large bowel content has a characteristic pattern of fine and evenly distributed air bubbles

Hepatic Opacity

Normal liver is soft tissue opacity Mineralization (can be biliary system or in the hepatic parenchyma) -Choleliths should be considered when focal mineral opacities are visible in the area of the gallbladder -Linear trails of mineralized opacities extending peripherally within the hepatic parenchyma are indicative of choledocholiths, or calculi within the bile ducts. *often incidental findings but can cause obstructions -Mineralization of the gallbladder wall has been associated with gallbladder carcinoma and cholecystitis -Hepatic parenchymal mineralization may be localized or diffuse and have a variety of patterns. Calcification of hepatic granulomas, abscesses, hematomas, neoplastic masses, or areas of hepatic necrosis can occur Radiolucent regions -represents gas in the biliary system, portal venous system, or hepatic parenchyma -Portal venous system: Severe necrotizing gastritis or enteritis (e.g. GDV), GIT ulceration, truama. -Gall bladder: Gas in or around the gallbladder occurs with emphysematous cholecystitis Gas lucencies within the biliary system can also be seen after surgery of the duodenum or biliary system -Hepatic Parenchyma: hepatic abscesses if they have gas forming organsisms

What does the most R arrow represent?

Normal lung

Is gall bladder sludge bad?

Not necessarily -intraluminal echogenic, dependent, mobile biliary sludge is present in up to 53% of asymptomatic dogs Its when its immobile we have a problem

Flexed dorsoplantar What is this useful for??

OCD!! -makes it so the calcaneus is away from the joint Not that difficult to do

If a fracture if highly suspected based on clinical findings..but nothing is seen on X-rays - what should we do?

Oblique views Small stress fractures or incomplete fractures may not have sufficient displacement immediately following the injury to allow detection. Follow-up radiographs in 7 to 10 days may be needed to detect these fractures as the fracture line becomes more conspicuous. The normal healing process begins with some resorption of the ends of the fracture fragments.

Osteosarcoma as a secondary event..what does this mean?

Occasionally, osteosarcoma develops secondary to another bone abnormality. For example, dogs with bone infarction are prone to develop osteosarcoma. Bone infarction, which is ischemic death of cellular elements of bone, may be idiopathic or caused by bone trauma, such as total hip arthroplasty. Dogs developing idiopathic polyostotic bone infarction and subsequent osteosarcoma are typically small-breed dogs (shelties and terriers) in contrast to the large breeds that typically develop primary osteosarcoma. Bone infarction also develops relatively commonly distal to the femoral component of a total hip prosthetic device Very rarely, a fracture or an internal fixation device will stimulate the development of a primary bone tumor Following tibial plateau leveling osteotomy (TPLO) surgery, 11 of 2464 dogs had an osteosarcoma develop at the TPLO site, supporting the very uncommon prevalence of this syndrome. The lag time from surgery until the identifica- tion of the tumor was approximately 4.5 years

Occipital Bone Malformation and Syringomyelia (Chiari-Like Malformation) What is this? List an unusual clinical sign it may cause

Occipital bone malformation may result in overcrowding of the caudal fossa, leading to obstruction of CSF flow, hydro- cephalus, and secondary syringomyelia. This hereditary defect, termed Chiari-like malformation, is common in the Cavalier King Charles spaniel, but is also found in other brachy- cephalic breeds. Clinical signs vary in severity and usually are seen between the age of 6 months and 2 years old; however, neurologic signs may not appear until later in life Clinically, dogs often present with persistent scratching of the shoulder region, with no dermatologic cause and thought to be a paraesthesia secondary to syringomyelia Radiographs are not useful, needs MRI

Occipital dysplasia What is this?

Occipital dysplasia is the dorsal extension of the foramen magnum, secondary to a developmental defect in the occipital bone It has been related to clinical signs of neurologic disease and is usually found in miniature and toy breeds *best found on CT Occipital dysplasia may be a normal morphologic variation in brachycephalic dogs

Small heart size!!

Occurs due to a reduction of circulating volume Think -Blood loss/hypolaemia -Dehydration -Addisons Radiographically, the heart appears small subjectively and may be retracted from the sternum. The lungs will usually appear overinflated, but this is an artifact causedby the reduction in cardiac size. Pulmonary vessels also appear small, leading to increased pulmonary hyperlucency

Hiatal diseases Think oesopheageal hernias, paraoesophageal hernias and gastroesophageal intussusception

Oesophageal hernias can be congenital or acquired. In the acquired form, weakness of the diaphragm, elevated abdominal pressure, and upper airway obstruction are predisposing factors.

What about seeing the dorsal tracheal membrane?

Often seen in asymptomatic dogs, the role of a visible dorsal tracheal membrane in tracheal collapse is understood poorly. In symptomatic small-breed dogs, the dorsal tracheal membrane may become stretched secondary to tracheal collapse and may be pathologically redundant. The greater the opacification superimposed on the tracheal lumen, the greater the chance that the patient has tracheal collapse.

The lower first molar

Often there is pocketing around the rostral aspect of the mandibular molar In this case if we can move this 2nd molar (and likely 3rd molar as they often have the same degree of periodontal problem) we have a chance of soft tissue reattachment for the 1st molar *make sure the root is well cleaned

Cat Gastric Axis

On VD the stomach is more steeply angled in a cat This makes the pylorus closer to midline.

L lateral!!

On the L lateral you can see the pylorus only has gas Lower green arrow on the R = pylorus Upper green arrow on the = duodenum So what is the opacity inbetween? The pyloric spincter! So this is a case of non obstructive foreign material. They had a feeling it was going to pass (and it did) so did not go to the surgery/induce v+

How do I tell its straight?

On the VD - look at the dorsal spinous processes -should be centred over the spine -the length of the ribs (should be equidistance) -the length of the ilium -the obturator foramen

There are some bone lesions where the transition zone concept does not apply Name one

One example is an infected fracture. The medullary cavity has been disrupted by the original fracture, and discriminating the effects of the infection versus the fracture on the appearance of the bone is usually not possible.

Medical management for obstructions

One paper showed that -37% of animals given medical management for a pyloric obstruction improved -17% for small intestinal obstruciton -11% if both pyloric and small intestinal So in cases where people cannot afford surgery, he will try medical management as long as they are aware there is a large risk it will not help The flip side of this is that when you take repeat X-rays - you should expect in the majority of cases the animal will still have that distended stomach/SI loop etc

What do you think caused this?

Osteopenia

Additional fracture terms

Pathologic Chip Fractures -usually from direct trauma -A fracture bed helps to identify this from being soft tissue mineralisation/ossification centre Slab fracture -usually cuboidal bones Avulsion fractures -occur at attachment sites of tendons, ligaments, or joint capsules and are caused by excessive forces placed on these structures that result in a piece of bone being pulled off of the parent bone. Avulsion fractures should have observable fracture beds Depression fracture -think skull, sinus.. Condylar, bicondylar, and supracondylar, T, and Y fractures are terms used to describe fractures involving the metaphysis and condyles Osteochondral fractures are defined as a disruption of articular cartilage along with a portion of subchondral bone. If the fracture fragment is loose within the joint, it is termed a loose body or joint mouse Fissure fractures are incomplete fractures that appear as thin radiolucent lines often arising from a complete fracture. Fissure fractures must be identified, because they often develop into complete fractures during reduction and fixation and compromise the repair.

Imaging of Portosystemic Shunts What is a portosystemic shunt?

Portosystemic shunts are congenital or acquired anomalies of the portal vasculature in which blood bypasses the liver and enters the systemic circulation directly CT with contrast medium is imaging of choice to evaluate the portal vasculature

Mediolateral shoulder

Palpate your landmarks and centre over the shoulder joint -feel the greater tubercle of the humerus and centre just in from that point Make sure the head and neck are extended -if they are flexed and down the spine will overly the shoulder Position in swimmers view - upper leg goes backward, under leg goes forward

What is one of the most common causes of extrahepatic biliary obstruction in the dog?

Pancreatitis

*don't memorise Table 47.7 lists diagnostic considerations for the more common patterns of bowel dilation.

Patterns of dilation include 1. focal/mild: one to three loops are involved, and luminal distentions are 1.5 to 2 times normal 2. focal/severe: one to three loops are involved, and luminal distention is greater than twice normal 3. generalized/mild: all loops are involved, and luminal distention is 1.5 to 2 times normal (Fig. 47.16); 4. generalized/severe: all loops are involved, and luminal distention is greater than twice normal.

Pharyngolaryngeal trauma or FB What would the most common cause of trauma be?

Penetrating injury e.g. stick, bite wound Gas opacities can be found in the subcutaneous tissues and between muscle and tissue planes. If linear, these represent emphysema, whereas more focal and rounded gas accumulation may indicate abscess. Emphysema has been reported in 83% of dogs with acute oropharyngeal stick injury and can extend to pneumomedias- tinum, pneumothorax, mediastinitis, and pleural effusion Fractures of the bone can also occur (high risk of contamination if exposed to the airway) Plant material is not generally visible radiographically but, when large enough, is detected easily using computed tomography (CT).

What is the risk with percutaneous biopsy of the prostate gland?

Percutaneous biopsy of presumed or suspected prostatic carcinoma is controversial in that there is a real possibility of seeding the tumor to the peritoneum or pelvic cavity. Cytologic examination of urine sediment acquired during a urethral catherization and flush of the prostatic urethra should be performed before biopsy is considered as this noninvasive procedure frequently is successful in confirming the presence of neoplasia.

DIVERTICULA, PERFORATION, AND FISTULA FORMATION

Perforation of the esophagus occurs either acutely because of a sharp foreign body or chronically because of slow pressure necrosis from a foreign body or neoplasia. Perforations can communicate with the mediastinum and/or the pleural space. Bony foreign bodies, a bodyweight of less than 10 kg, and esophageal foreign body present for more than 3 days are considered significant risk factors for complications. Complica- tion rates of esophageal foreign bodies are reported to be 12.7% and include perforation, stricture, diverticula, periesophageal abscess, pneumothorax, pleural effusion, and respiratory arrest. Cervical perforations have a better prognosis than thoracic.

p33

Periosteal proliferation is sometimes seen on the ventral aspect of the caudal lumbar vertebrae and pelvis because of regional metastasis from prostatic neoplasia. Periosteal proliferation in this region from metastasis can also be caused by other urinary tumors or hematogenously metastasizing tumors of the pelvic canal or perineum.

How big shoudl the peripheal pulmonary arteries and veins be?

Peripheral pulmonary arteries should be approximately the same size (matched in size) as their associated pulmonary vein. With regard to absolute size of the caudal lobe pulmonary artery and vein, a convenient comparison is the relative size of a caudal lobe pulmonary artery to the thickness of the ninth rib in the VD or DV view where they intersect. The summation shadow created by overlap of a caudal lobe pulmonary artery and the ninth rib should normally have sides of equal length, meaning the vessel and rib are the same size Pulmonary vessels are dynamic, however, and their size can change relatively quickly, being a function of intraluminal pressure and volume. Dehydration from diuretic administration or increased intravascular volume from overzealous intravenous fluid administration can lead to rapid changes in vessel size, so interpretation of vessel size must be made with knowledge of any recently administered medications or therapies

3. Perirenal fluid

Perirenal or subcapsular fluid may be the result of acute renal failure, urine leakage, ureteral obstruction, hemorrhage, abscessation, perirenal pseudocysts, and neoplasia.

Rarely, gas will occur spontaneously in the wall of the colon What is this called? What does it indicate?

Pneumatosis coli In some patients can be incidental and benign however can also be a sign of more serious disease e.g. intestinal infarction (and can lead to pneumoperitoneum)

Look at the cecum!

Pneumocolon can help to identify where the FB is sitting He said you can just use a red tubber catheter to put air in - cheap and easy! keep it in to make sure youve put enough in

In the above case - we can't see the pylorus clearly on the R lateral because the patient is v+ so much that the gas is gone What can we do about this?

Pneumogastrogram Really safe!! use carbonated fluids

ANY cavitary lesion (bulla or nasty) has the potential to rupture and cause...

Pneumothorax

Polypoid cystitis

Polypoid cystitis is uncommon in dogs and can vary in sonographic appearance ranging from pedunculated, ovoid, or nodular urinary bladder wall changes Polypoid cystitis is often located in the cranioventral and craniodorsal portions of the urinary bladder, which may aid in differentiation from neoplasia, such as transitional cell carcinoma, which is usually located near the urinary bladder neck. Follow-up sonographic evaluations should be made after treatment of polypoid cystitis to reevaluate the masses. Biopsy is needed for definitive diagnosis.

Feline nasopharyngeal polyps

Polyps are non-neoplastic growths originating from the mucous membrane of the auditory tube or middle ear. *interesting to know they arise from this location Nasopharyngeal polyps generally occur in younger cats and can extend into the external ear canal, the osseous bulla, or the nasopharynx. Although rare, cats can have multiple polyps.188 Cats may have signs of middle ear disease, rhinitis, or upper airway disease secondary to the space- occupying polyp. Signs of otitis media (increased soft-tissue opacity of the affected bulla) or nasopharyngeal obstructionmay be noted on radiographs

Trachea and larynx

Positioning is very important for assessing the pharyngolaryngeal region -The lateral view with the head mildly extended is most useful -obliquidy causes structures like the soft palate to look thicker High ma and low kvp recommended

Postoperative Stomach -appearance can mimic disease

Post operatively functional disturbances of motility of the stomach and intestinal tract, paralytic ileus and vomiting are common No displacement of the stomach should be expected post subtotal gastrectomy or gastric biopsies If a gastropexy was done, expect the pylorus to be in close proximity to the right lateroventral abdominal wall. Radiographically a caudoventral displacement of the pyloric antrum caudal to the last rib might be noted Radiographs are also frequently done post gastrotomy tube placement

Dilated Cardiomyopathy

Predisposed breeds: dobermans, great danes, cocker spaniels, boxers • The radiographs may be normal in some dogs with dilated cardiomyopathy. • Generalized cardiomegaly is caused by volume overload or ventricular dilation. • Left atrial dilation may be present because of volume overload or mitral valve dysfunction from a change in shape of the mitral annulus as a result of cardiac dilation. • Pulmonary vein dilation from mitral valve dysfunction and regurgitation or from fluid retention is seen. • Parenchymal pulmonary artery dilation from fluid retention can be stimulated by decreased renal perfusion, leading to activation of the renin-angiotensin system. • Possible pleural effusion, hepatomegaly, and/or ascites from right-sided heart failure is often seen. • Mixed interstitial and bronchial pattern caused by atypical pulmonary edema. Strictly on the basis of radiographic appearance, this radiographic pattern is more typical of inflammatory allergic airway disease, but a bronchointerstitial pattern is also common in large dogs with dilated cardiomyopathy as a manifestation of left heart failure. The pathophysiologic cause of peribronchial edema developing as opposed to alveolar edema is not understood.

Gastric Neoplasia What is most common in the dog?

Primary gastric neoplasia is rare -Adenocarcinoma is the most common malignant gastric tumor in dogs. Most often found in the pyloric portion Polyps (aka glandular hyperplasia) also occur (these are often incidental findings) Inflammatory lesions can also result in thickening of the gastric wall and have similar imaging findings as neoplastic lesions.

The descending colon

Proximally it lies near the left kidney and ureter, spleen, and small bowel. The right ureter travels directly adjacent to the colon wall in the mesocolon towards the bladder neck. The mid-portion of the descending colon lies adjacent to the small bowel, urinary bladder, and uterus. Because it is less fixed, the mid-portion of the descending colon has a variety of normal positions in the caudal left abdomen. In some dogs the descending colon is positioned along or slightly right to the median axis of the body. The distal portions of the descending colon and rectum are also closely associated with the urethra, the medial iliac, hypogastric and sacral lymph nodes, the prostate or uterus and vagina, and the pelvic diaphragm.

Normal variations of the duodenum

Psuedoulcers String of pearls

Important

Pulmonary vessels projected end-on will create a solitary circular opacity, and these are often confused with a pulmonary nodule. End-on pulmonary vessels are usually found adjacent to a bronchus, and many times it is possible to see the connecting portion of the vessel, projected side-on, extending peripherally from the "nodule" This connecting opacity has been referred to as a tail. Is this similar to kotiro?

Pulmonic Stenosis

Pulmonic stenosis leads to restriction of flow from the right ventricle into the pulmonary artery. • Dilated main pulmonary artery is caused by turbulence. • Enlarged right ventricle is caused by hypertrophy related to increased resistance associated with ejection. • Parenchymal pulmonary vessels are usually normal in size; but if right-sided heart failure develops, the pulmonary vessels may be small because of reduced cardiac output

Pulp exposure

Remember the X-ray is only 2D so if you cant find anything on your physical exam but there appears to be pulp exposure on the X-ray, if the pulp width is normal this may be 'artefact'

Radiographic signs of diaphragmatic disease

Radiographic changes observed most frequently with diaphragmatic disease include 1. general or focal loss of the thoracic diaphragmatic surface outline 2. changes in diaphragmatic shape and position The thoracic diaphragmatic surface outline will not be visualized radiographically if soft tissue or fluid contacts the surface.

Brachycephalics

Radiographically, elongated soft palate and soft palate edema appear as an extension and thickening of the soft palate beyond the tip of the epiglottis, and subsequent narrowing of the nasopharyngeal and oropharyngeal diameters

Otitis What radiographic views are best

Radiographs are very useful in diagnosis otitis media -often secondary to otitis externa Otitis interna is based on clinical signs are radiographic changes are non sensitive for this Radiographic views 1. Lateral oblique 2. Open mouth In advanced disease, exuberant bony proliferation may involve the petrous temporal bone or the TMJ Often clinical and subclinical ear disease will be identified in cats undergoing CT imaging of the skull.178 In 310 cats undergoing CT imaging of the skull, 103 had middle ear disease and 34% of these had no clinical evidence of ear disease and most had concurrent nasal disease,178 consistent with bullous effusion.

ARticulation of the vertebrae

Remember these are the lamina The intervertebral disc spaces of the cervical vertebrae become progressively wider between C2-C3 and C6-C7. The T10-T11 intervertebral disc space is narrower than adjacent disc spaces in most dogs.

Pylorogastric Intussusception What is this?

Rare in dogs, not reported in cats Radiographically, distension of the stomach and a large mass effect extending luminally into the pylorus to fundus area may be noted On U/S you can see displacement of the pylorus and duodenum into the pyloric antrum and fundus

ML What can be confused as a myelolipoma that is not benign?

Rarely, mast cell tumors have been reported to cause hyperechoic nodules in the spleen

Radiographic evaluation of bone healing What does ABCDS? stand for

Recommended every 4-6 weeks or sooner if clinical signs indicate an acute change in condition or the development of pain/swelling at the fracture site. ABCDS is recommended to evaluate orthopoedic X-rays for healing A= alignment B= Bone C=Cartilage D= Device S= soft tissues For alignment - try and to get repeat X-ray angles very similar to the initial views for comparison For cartilage - assess the joint -The apposition of articular fracture fragments as indicated by alignment of the subchondral bone is an important radiographic sign -The presence of joint effusion with subchondral bone lysis and periosteal new bone that is more irregular than normal callus may indicate a septic joint. Soft tissue -Soft tissue emphysema and swelling is seen normally immediately post-operatively but should resolve in 7 to 10 days -Air pockets that occur after the initial emphysema resolves are not common but when present suggest infection. Soft tissue atrophy is a common sign of disuse and signals significant lameness or disuse of the structure. -Although rare, fracture- and implant-associated sarcomas can occur years after a fracture repair

How do we evaluate the lateral trochea of the talus? (as in normal DP views the calcaneus supreimposes)

Red arrow = lateral trochea see in this view the distal end of the fibula close to the red arrow too (thats how we know its the lateral side)

What is redundant oesophagus?

Redundant esophagus is often an incidental finding in young brachycephalic breeds, such as bulldogs and shar-peis. Survey radiographs may be normal, or focal dilatation of the esophagus with gas can be seen at the thoracic inlet.

Is renal lymphoma unilateral or bilateral?

Renal lymphoma tends to occur bilaterally and causes enlarged, irregularly shaped kidneys with a hyperechoic cortex. A subcapsular, hypoechoic rim is associated with renal lymphoma in cats

Focal or multifocal kidney abnormalities 1. Mineralization

Renal mineralization, because of nephrolithiasis or dystrophic mineralization, is common, especially in older patients. All types of nephroliths are detectable ultrasonographically and are characterized by a hyperechoic surface and a distal acoustic shadow. Dystrophic mineralization in the renal parenchyma by itself is of questionable clinical significance but is often accompanied by other chronic renal changes.

Hydro

Renal pelvis dilation greater than 13 mm has a high specificity for ureteral obstruction

Osteophytes Where do these form?

They are seen as bony outgrowths at the periphery of articular cartilage. They start as cartilage and then ossify They occur as a component of degenerative joint disease

Theory of joint incongruity

Results in altered loading when incongruent If the radius is short, the medial coronoid process can overload and fragment Incongruity is hard to diagnose radiographycailly CT is much better *this is because 1mm or less incongruity can result in remodelling and issues

Rank CT, MRI and X-rays in terms of who is best for 1. Resolution 2. Contrast

Resolution 1. Radiographs 2. CT 3. MRI Differences are minor Contrast 1. MRI 2. CT 3. Radiographs Differences are major

Which long bones do we tend to see HOD in?

Resulting bone lesions are generally bilaterally symmetric and involve the metaphyses of long bones, particularly the distal radius, distal ulna, and distal tibia. Although hypertrophic osteodystrophy is usually self-limiting and resolves after a few weeks, more severe involvement can ultimately result in abnormal/premature physeal closure and subsequent skeletal deformity

What is Gastroesophageal Intussusception?

Results from invagination of the stomach +/- other organs into the Oesophagus Uncommon but emergent as lack of blood supply to the stomach causes rapid decline of the patient Only possible if an underlying condition exists e.g. -megaoesophagus -chronic vomiting -dilation of the oesophageal sphincter On radiographs a large well-defined soft tissue mass is usually present in the caudal esophagus with gas in a dilated esophagus cranial to the mass.

Nasal rhinitis

Rhinitis secondary to bacterial infection, or corticosteroid- responsive rhinitis with lymphoplasmacytic infiltrates, can have a variable radiographic appearance in dogs and cats. Depending on the chronicity and severity of rhinitis, there may be evidence of destruction of conchae and of bony erosion Chronic rhinitis and sinusitis in cats are common sequelae to viral upper respiratory tract disease Radiographic changes can range from none in mild infections to an increased opacity of the nasal cavity and frontal sinuses with conchae and vomer bone destruction in severe infections. *neoplasia or aspergillosis are more likely to result in conchae destruction

Congenital and Developmental anomalies

Ribs -Rudimentary ribs are sometimes present on the seventh cervical vertebra. -Anomalous ribs can appear as transverse processes on the thirteenth thoracic vertebra -Ribs may also be hypoplastic or absent on the thirteenth thoracic vertebral segment Sternal (may be linked with peritoneopericardial diaphragmatic hernias) -A reduction in number or fusion may occur -Pectus carinatum (ventral displacement of the sternum or pigeon chest) *caused by idiopathic overgrowth of the costal cartilage - Pectus excavatum (dorsal displacement of the sternum or funnel chest) *can be associated with cardiac and respiratory abnormalities *congenital issue. Cause unknown Most congenital thoracic wall defects are not repaired surgi- cally unless they are associated with life-threatening complications.

Which one is best?

Right view Left not straight - makes it look like theres pathology between discs

Right sided heart failure.. List 3 possible radiographic signs

Right-sided heart failure usually includes some or all of the following radiographic signs: bilateral pleural effusion with varying degrees of secondary pulmonary atelectasis, ascites, and hepatosplenomegaly. If the heart is visible, some changes of right heart enlargement are likely to be present.

What causes both the vein and artery to be smaller?

Right-to-left shunts -Tetralogy of Fallot -Ventricular septal defect with pulmonic stenosis -Severe pulmonic stenosis with decreased cardiac output Hypovolemia Shock Dehydration

Agressive vs non aggressive

Roentgen signs are useful for describing the appendicular skeleton however also classifying as aggressive vs non aggressive is very important Whether a bone lesion is aggressive or nonaggressive is based on the assessment of three criteria: 1) whether or not there is destruction of the cortex 2) the character of any periosteal reaction 3) the distinctness of the boundary between the bone lesion and the normal bone, called the transition zone Note that whether a lesion is primarily radiolucent (loss of bone) or radiopaque (production of bone) has no bearing on whether the lesion is aggressive. You only need one characteristic to class as aggressive. The more characteristics you get does not correlate with the biologic aggressiveness of the lesion. But, importantly, the absence of radiographic evidence of aggressiveness usually means no biologic aggressiveness.

SLOB Separating 3 rooted teeth e.g. 108

SLOB The image of the roots will follow the generator head on the lingual surface where the opposite will happen on the buccal surface So if you rotate the generator head rostrally you will bring the lingual root closer to the front of the plate because of the way the beam is generating

The most common transitional anomaly at the lumbosacral junction is...

Sacralization of L7, where one side of L7 has the form of a vertebra with a transverse process while the opposite side has the form of a sacrum and articulates with the pelvis (Fig. 9.33). The presence of a lumbosacral transitional anomaly predisposes dogs to the development of lumbosacral disk herniation and nerve root compression,8,9 caused by altered biomechanical loading. Search pattern for spine (1) the number of vertebral bony segments in each anatomic region; (2) in dogs and cats, the number of ribs in the thoracic spine; (3) presence of transitional anomalies or other congenital malformations; (4) alignment of individual vertebral elements; (5) the symmetry of the vertebral canal throughout the spine; (6) the integrity of the neural arch of individual vertebrae; (7) changes in shape, opacity, or margin- ation of vertebral bodies; (8) changes in shape, opacity, or margination of articular processes; and finally, (9) character of paraspinal soft tissues.

Is sand an issue?

Sand impaction can also cause intestinal obstruction and this tends to be in the distal small intestine Radiographically, there is segmental dilation of the bowel that contains mineral opaque material. Although sand particles are small it is proposed that the sand coalesces and dehydrates to form the obstruction. Sequential radiographs can be used to monitor progression of the sand but if no progress is observed a laparotomy should be considered

Scottish fold cats

Scottish fold chondro-osseous dysplasia (SFCOD) is an inherited autosomal dominant trait that causes defective cartilage maturation. If severe can be crippling

Septic arthritis

Septic arthritis is diagnosed infrequently in small animals, with the incidence being lower than that of immune-mediated joint disease. Septic arthritis is difficult to diagnose radiographically. Initial radiographic changes are usually limited to joint effusion and periarticular swelling. Polyarticular septic arthritis may occur as a result of bacteremia associated with an isolated focus of infection (endocarditis, discospondylitis, or omphalophlebitis) or in conjunction with a systemic disease (as in Mycoplasma arthritis, canine leishmaniasis, or feline caliciviral lameness).44 Polyarticular septic arthritis must be differentiated from immune-mediated joint disease. The former is more likely to affect the larger, more proximal joints of the appendicular skeleton, whereas the latter more commonly affects the joints nearer the distal extremities Septic arthritis is being identified increasingly in joints that have chronic degenerative joint disease. Initial radiographs are characterized by degenerative joint disease, often leading to inappropriate therapy for the infection. Radiographs made 2 to 4 weeks later reveal more aggressive signs of periosteal new bone formation and intraarticular bone destruction. Septic arthritis should be suspected when acute lameness and joint pain are identified in individual animals whose degenerative joint disease has been controlled previously.

What is HOD? Hypertrophic osteodystrophy Signalment Cause Clinical signs except for lameness

Signalment: Systemic disease that affects large and giant breed dogs between 2 and 7 months Breeds at greatest risk for hypertrophic osteodystrophy include boxers, Great Danes, Irish setters, and Weimaraners The cause is unknown, but over supplementation of minerals and vitamins, hypovitaminosis C, and suppurative inflammation without isolation of infectious agents have all been proposed. Clinical signs, including marked pyrexia, diarrhea, footpad hyperkeratosis, leukocytosis, anemia, and pneumonia, are occasionally seen with hypertrophic osteopathy, lending credibility to the possibility of a systemic infection as a cause for this disease.

Aseptic necrosis of the femoral head Signalment: Cause:

Signalment: Young toy/small breeds Cause: Compromised blood supply to the femoral capital epiphysis

Osteochondrosis and osteochondritis Dissecans Signalment Age of onset Radiographic signs

Signalment: Young, rapidly growing, Large breed dogs -common cause of lameness in these breeds These lesions tend to be bilateral to X-ray both sides~~ Age of onset: Typically 6-9 months Cause: Cartilage necrosis resulting in a loss of normal ossification -failure of endochrondral ossification (probably due to vascular reasons) - this results in cartilage filling in the gaps but then this necroses due to lack of nutrients (synovial fluid can't keep it happy) Extremely uncommon in cats (he thinks we will be unlikely to ever diagnose this)

Talk small intestinal FB

Signs -FB present -gas/fluid oral to the obstruction (and more normal post obstruction) - this is where two populations of bowel comes from (AKA segmental dilation) -hairpin turns -stacking of SI

Multiple types of periosteal reaction can be seen with ostesarcomas. List 3

Smooth Spiculated Columnar Although bone infections may have an active periosteal reaction, extremely aggressive and amorphous types of periosteal reactions are more commonly associated with tumors.

Adequate flexion

So a maximally flexed elbow view should be part of every dog elbow study

Ex

So easy to see this when you are looking at a normal comparatively More difficult when using your mental database So unstructured interstitial disease leads to a vague, hazy increased opacity to the background of the lung. It blurs the vascular margins Difficult diagnosis to make Often missed OR overdiagnosed

Coughing and dogs with a left sided heart murmur..

Some dogs with a dorsally displaced tracheal bifurcation will also have narrowing of one or both principal bronchi. This narrowing is most likely not due solely to impingement from the subjacent dilated left atrium but more likely to coexisting bronchial chondromalacia with dynamic bronchial collapse. The enlarged pulsating left atrium will be more likely to contribute to narrowing of a malacic bronchus than a normal bronchus, and the malacic bronchus will also be subject to dynamic airway collapse. Dogs with left atrial dilation and bronchial narrowing from bronchomalacia will typically exhibit a cough, which often misleads the clinician to conclude erroneously that the patient is in heart failure. In fact, in an evaluation of 206 dogs with mitral valve disease, there was not a statistical association between the presence of pulmonary edema and coughing.11 Therefore, causes of a cough other than heart failure should always be considered in dogs with a heart murmur.

Spina bifida List two predisposed breeds

Spina bifida results from the lack of development of the vertebral arch and may be associated with neural tube defects MRI best to diagnose -may see split spinous process on X-ray Spina bifida is most common in bulldogs and Manx cats.

Splenic Abscess

Splenic abscesses are uncommon, but they can have a complex appearance similar to hemangiosarcoma or hematomas

When might I see gas in the spleen?

Splenic torsion Splenic abscesses

What is splenic torsion?

Splenic torsion occurs when the spleen rotates around its mesenteric axis, resulting in complete occlusion of venous drainage and eventual arterial occlusion. This results in marked splenomegaly, as well as an atypical splenic location. -can be on its own or with GDV It may acquire a reverse C-shape on the lateral view or may simply appear as a mass in the ventral abdomen The proximal extremity of the spleen may not be visualized in the normal left craniodorsal location because of the malposition or accompanying peritoneal fluid.

Poll3 Dog thats eaten tissue paper.

Stomach appears normal in size Pyloric region - soft tissue opacity -fluid? material? other..

What about improving the accuracy of shoulder OCD lesions?

Supinated views may help

Enlargement can be symmetrical or asymmetrical How is this judged?

Symmetric enlargement will be due to a diffuse disease (e..g prostatitis and hypertrophy) Asymmetrical examples would be neoplasia and large cysts Prostatic symmetry is judged by the shape of the prostate gland and the relative mass of the prostate gland with respect to the neck of the bladder and the pelvic inlet. -If prostatomegaly is uniform, urinary bladder displacement is cranial along the floor of the abdomen. -If prostatomegaly is eccentric the direction of the urinary bladder may be different The other major radiographic sign of prostatomegaly is dorsal displacement of the colon. Prostatic enlargement may also cause narrowing of the lumen of the colon or rectum. This compression may be visible radiographically, or the colon may simply become confluent with the prostate mass at the pelvic inlet. Prostatic disease that results in urethral stricture may result in severe urinary bladder distention, which is then secondarily responsible for the displacement of the abdominal structures cranial and dorsal to it.

VD skull

Symmetry is important Try and get the hard palate paralell to the table top (need to tip the head right back)

Traumatic injuries What way does TMJ luxation tend to be?

TMJ luxation can occur in both dogs and cats after external trauma. In the cat, TMJ luxation often occurs after the cat has jumped from a height, and in both dogs and cats, dislocation can occur secondary to being hit by a car.193 The TMJ is capable of luxation without fracture because it has considerable lateral sliding movement, and the synchondrosis of the mandibular symphysis allows independent movement of the mandibular rami. Dislocation of the TMJ tends to be in the rostrodorsal direction (Figs. 11.31 and 11.32), because ventrocaudal luxation is prevented by the retroarticular process of the temporal bone. Dogs and cats with TMJ dislocation are unable to close the mouth completely, have dental malocclusion with the mandible displaced to one side, and display excessive salivation.44,195 Luxation is most often unilateral; it may occur alone or with concomitant fractures of the retroarticular process, mandibular fossa, and zygomatic process of the squamous temporal bone or with the condyloid process of the mandible.195

Radiographic Signs of Major Vessel Enlargement 2. Main pulmonary artery

The main pulmonary artery is not seen normally as a separate structure, but when it dilates sufficiently in dogs, it will appear as a focal bulge in the 1:00 o'clock position in VD or DV views Uncommon DDX: pulmonary hypertension, as from heartworm infection turbulence, as from pulmonic stenosis or patent ductus arteriosus.

Tension Pneumothorax What is this?

Tension pneumothorax occurs when pleural space pressure exceeds atmospheric pressure during both phases of respiration. Tension pneumothorax results from a check-valve mechanism at the origin of pleural space air. Air enters the thorax with each breath but cannot escape. In tension pneumothorax, increased pleural pressure causes the lung to collapse to a greater degree than even its maximal collapse in an open pneumothorax. Thus it may no longer maintain the shape of a lung but may assume the appearance of an amorphous opacity compressed against the midline. With unilateral tension pneumothorax, the increased pleural space pressure will cause a contralateral mediastinal shift (this is opposite to a normal pneumothorax where the heart moves to the side with the most air as the lung collapses) Tension pneumothorax may also result in caudal displacement of the diaphragm to the degree that its costal attachments become visible; this is termed tenting of the diaphragm Tension pneumothorax is uncommon, but it is important to recognize because it is potentially fatal and requires immediate thoracocentesis.

Canine osteosarcomas Age of onset Signalment Common sites Thrall is a big fan of aspirates (FNA) of bone lesions - he feels very unlikely to cause rupture of the bone and thinks they can be very diagnositic

The age distribution of canine osteosarcoma is bimodal with a small peak in incidence at approximately 2 years of age and then a larger peak in incidence later in adult life. Typically large and giant breeds Common osteosarcoma sites in the forelimb are the proximal humerus and the distal radius (away from the elbow), and in the hind limb, the distal femur and proximal tibia (toward the stifle). Tumors in the distal tibia are also common. Can be lytic, productive or mixed

Distal to what joints are X-rays termed dorsopalmer or dorsoplantar?

The antebrachiocarpal or tarsocrural joint

What does calvaria mean?

The calvaria comprises the bones of the brain case, with the occipital bone forming the base of the skull. The occipital crest is the most dorsocaudal aspect of the skull , and the occipital condyles are caudoventral as seen on lateral radiographs. The foramen magnum, centered between the occipital condyles, forms an orifice for passage of the spinal cord.

What location for OCD lesions is most common?

The caudal humeral head** by far the most common *small osteophyte also present on the caudal margin of the glenoid for the R shoulder (bottom image) Also a small osteophyte on the caudal margin of the humeral head ON the L side the ocd lesion is more subtle - we see more of a flattening of the humeral head

Radiographic Signs of Major Vessel Enlargement 1. Caudal vena cava

The caudal vena cava can enlarge in response to increased central venous pressure (but its insensitive) -Should not be more then 1.5x the diameter of the descending aorta

What is the cecum? How does it appear different in the cat vs the dog?

The cecum is a diverticulum of the proximal colon The canine cecum appears semicircular and compartmentalized and normally contains some intraluminal gas. -this allows it to be seen in the right mid abdomen on most X-rays. -The canine cecum joins the colon via a cecocolic junction, which is separate from the ileocolic junction. The feline cecum is usually not visible on survey radiographs. It is a short, cone-like diverticulum of the ascending colon with no distinct cecocolic junction and no compartmentalization. The feline cecum rarely contains gas or feces.

Radiographic Signs of Specific Cardiac Chamber Enlargement 3. Right Ventricle

The changes described here apply mainly to the dog as identification of right ventricular enlargement in the cat is not common The right ventricle undergoes hypertrophy in response to increased afterload, as with pulmonic stenosis or pulmonary hypertension (e.g. heartworm) Because the right ventricle is normally in contact with the sternum, right ventricular enlargement, whether from dilation or hypertrophy, often causes an increased sternal contact in the lateral view -In the average dog, the amount of cardiac contact with the sternum ranges from 2.5 to 3 intercostal spaces; thus sternal contact in excess of 3 intercostal spaces is consistent with right ventricular enlargement *some barrel-chested breeds, such as the bulldog, can normally have more than 3 to 3.5 intercostal spaces of contact* Right ventricular hypertrophy can also lead to the cardiac apex being displaced dorsally from the sternum in lateral view. In VD or DV views, a hypertrophic right ventricle appears more rounded and protrudes farther into the right hemithorax than normal, giving the cardiac silhouette a pronounced reversed letter D shape. However, care should be taken to not over-read the more rounded appearance of the right ventricle and judge it to indicate a "reversed letter D shape," because essentially all normal dog hearts have a somewhat rounded shape to the right ventricle with the left ventricle being straighter in shape.

3. Transition Zone

The character of the junction of the bone lesion with the adjacent normal bone is termed the transition zone. The transition zone is typically evaluated in the medullary cavity of the bone. The host bone is more able to contain a less aggressive bone lesion and the transition zone between the lesion and the host bone will be easy to define radiographically. In aggressive bone lesions, the host bone is unable to contain the lesion, and there is no demarcation, or incomplete poorly defined demarcation, between the lesion and the host bone.

Vessels2

The common bile duct is immediately ventral to the portal vein but is visible more consistently in the cat, where it can usually be followed to the duodenal papilla Normal intrahepatic bile ducts are not visible.

2. Tarsus

The common calcaneal tendon, or Achilles tendon, is composed mainly of the tendons of flexor digitorum superficialis and gastrocnemius muscles, with contribution of tendons from biceps femoris, semitendinosus, and gracilis muscles. It inserts onto the calcaneal tuberosity. Chronic desmopathies of the Achilles tendon cause soft tissue swelling, occasionally containing dystrophic calcification

What should the radiographic field include? Where should the X-ray beam be focused?

The field of view should include the joint proximal and distal to the bone of interest. If a joint is being investigated, the primary x-ray beam should be centered on the joint.

Radiographic appearance of the mediastinum - cranial

The cranial mediastinum immediately ventral to the trachea normally appears homogeneous in a lateral radiograph as a result of border effacement. This homogeneity is caused by the collective opacity of the left subclavian artery, brachiocephalic trunk, cranial vena cava, and mediastinal lymph nodes. In lateral radiographs, the mediastinum just ventral to the trachea is more radiopaque than the mediastinum just dorsal to the sternum because of the greater thickness just ventral to the trachea In obese patients, the cranial mediastinum will be increased in width because of fat accumulation, and this can be misdiagnosed as a pathologic mass There are two mediastinal reflections that can be seen radiographically

What is the red arrow pointing to?

The duodenum This is a normal abdomen If you do your views as L lateral, VD and then R lateral more likely to trap gas in the pylorus/duodenum which he likes! Helps to rule out a proximal FB *be careful as the older generation of radiologists were taught o interpret gas in the duodenum as enteritis/pancreatitis

Recommended order of operations

The following parameters can be evaluated in order 1) number of bones involved 2) the region of bones involved, for example, diaphysis versus metaphysis versus epiphysis, or a combination 3) whether or not long bones or joints alone are involved or if bones and joints are involved 4) the overall opacity of the skeleton 5) the relative appearance of the cortical bone versus medullary bone 6) the presence or absence of a periosteal reaction, and whether it is irregular or not 7) integrity of the cortex 8) the shape of the bones compared with what would be expected in a comparable normal animal 9) the character of the transition zone; and finally 10) character of adjacent soft tissues. In addition to having an organized search pattern, it is also helpful to scrutinize appendicular radiographs with a preconception of what disease might be found in a particular region in a particular patient. This is particularly true in young canine and feline patients, where developmental and juvenile bone diseases are often characterized by very specific findings. Examples are close examination of the (1) proximal margin of the anconeal process in dogs at risk of having elbow dysplasia (2) proximal margin of the lateral ridge of the talus in dogs at risk for tarsal osteochondrosis (3) distal radial and ulnar physes in young dogs at risk for hypertrophic osteodystrophy. It is critical that this focused approach be used only as an ancillary method; it is a way of double checking, so to speak, that all possibilities have been addressed.

Order of operations for skull

The following regions can be searched in order: (1) calvarium, (2) tympanic bullae, (3) temporomandibular joints, (4) stylohyoid bone and guttural pouches (horse only), (5) maxillary and mandibular bone, (6) maxillary and mandibular teeth, (7) nasal passage, (8) pharynx, and finally (9) the frontal/conchal/ maxillary sinuses.

Is the heart acutally "elevated" from the sternum in pneumothorax?

The heart is not actually elevated but displaced into the dependent hemi- thorax because of a lack of underlying inflated lung to support the heart in its normal midline position Although pneumothorax is the most common cause of the appearance of elevation of the cardiac silhouette on the lateral view, this can also occur with decreased heart size, in normal dogs with an extremely deep thoracic cavity, and in patients with hyperinflated lungs

What sphincter attaches to small intestine to the colon? Is it visible on X-rays?

The ileocolic sphincter connects the distal ileum to the ascending colon The distal ileum enters the ascending colon from a medial direction This circular sphincter is not visible on survey radiographs, but it can be identified as a filling defect when barium is present in the colon adjacent to the sphincter.

What am i seeing here?

The images show the use of the inherent gas as a contrast medium to confirm a gastrointestinal foreign body. In the right lateral view (R), there is mottled gas and soft tissue opacity in a moderately focally dilated small intestinal loop (black arrow) in the cranial ventral region. Moderate gas and fluid distention of the stomach is also evident. In the left lateral view (L), the redistribution of gastric gas provides contrast for identification of a soft tissue foreign body in the pylorus and mild plication of the proximal duodenum (white arrows). These findings confirm a fabric- type foreign body in the stomach with a linear component extending into the duodenum and proximal jejunum.

Hip dysplasia in cats Where do we see degenerative signs in cats?

The incidence of hip dysplasia in domestic shorthaired cats, based on standard hip radiography, has been estimated at 6.6%.31 The incidence is higher in purebred cats (12.3%), with some breeds, such as the Maine coon cat, having an incidence of 18% to 21% Unlike canine hip dysplasia, most degenerative changes in cats appear on the craniodorsal acetabular margins, with a low incidence of degenerative remodeling reported on the femoral head and neck.

1. Increased synovial fluid -what silhouettes with synovial fluid? What is the infrapatellar fat pad sign?

The joint cartilage, synovial fluid, synovial membrane, and joint capsule cannot be differentiated, because they are all of soft tissue opacity In the stifle, the infrapatellar fat pad sign may be used to evaluate synovial volume. The normal infrapatellar fat pad is identified readily on lateral stifle radiographs as a relatively radiolucent triangular region immediately caudal to the patellar ligament When stifle synovial mass increases, either from increased synovial fluid or soft tissue, a combination of inflammatory response and effusion causes the shape of the fat pad to be altered and the fat pad to become less visible.

2. Altered thickness of the joint space Is this useful radiographically?

The joint space is the region of soft tissue opacity between subchondral bone surfaces It consists of two layers of articular cartilage and synovial fluid The space can be wider if more fluid (acute) or decreased with degradation of cartilage These changes in joint space width are rarely diagnosed radiographically as a result of small animal patients not being radiographed while bearing weight and also because of inconsistency between the orientation of the primary x-ray beam and joint space.

What would some signs of non union be?

The key factor in distinguishing a nonunion fracture from a delayed union fracture is that healing has ceased and will not progress without intervention. Determination of a nonunion is subjective but relies on 1. lack of progression of a healing callus 2. remodeling of the callus at the fracture ends without bridging 3. lack of increase in opacity of the fracture line, and duration of the healing process. Some fractures that appear to be nonunion may eventually heal, given enough time. However, the length of time is greater than the normal healing time, and the outcome is doubtful. Intervention with improved stabilization and possible bone grafting is used commonly to increase the chance of a successful union

What is the difference between osteochondrosis and osteochondritis dissecans?

The main distinction between the two is if we can see a fragment If we can see a fragment its called osteochondritis dissecans The differentiation is vague (often there is a fragment but we cant see it as its not mineralized)

Degenerative joint disease is a common sequel to develop- mental disorders of the immature skeleton, particularly when..

The lesion involves joints or causes limb deformity Often the most pronounced radiographic findings are those of the degenerative changes, which can mask the original devel- opmental lesion.

Cauda equina syndrome

The lumbosacral junction is unique because of its structure, relatively wide range of mobility, and the fact that it houses nerve roots of the caudal aspect of the spinal cord. In dogs, the spinal cord terminates near the level of L6 or L7, depending on breed,70 and at L7 in cats.71 The cauda equina refers specifically to the collection of nerve roots that lie within the vertebral canal caudal to the termination of the spinal cord.72 These nerve roots stream caudally from their respective sacrocaudal cord segment, exiting the vertebral canal through intervertebral foramina, caudal to their origin in the spinal cord. This is because the spinal cord is shorter than the vertebral column insofar as they have dif- ferential fetal growth rates. Thus the spinal nerves descending from the L7 spinal cord segment exit the vertebral canal at the L7-S1 intervertebral foramina and are lateral to the remainder of the cauda equina. Numerous degenerative, inflammatory, traumatic, and neoplastic conditions can affect the lumbosacrum of dogs and cats and result in result in pain, neural dysfunction, and exercise restriction.73,74 Because most of these conditions involve the cauda equina, the term cauda equina syndrome has been applied. Other terms used in conjunction with cauda equina syndrome include lumbosacral disease, lumbosacral stenosis and degenerative lumbosacral stenosis, lumbosacral malarticulation malformation, lumbosacral instability, and others Cauda equina syndrome is uncommon in cats, but sacrocaudal trauma or a tail pull injury with avulsion of the cauda equina may be confused with typical signs of cauda equina syndrome Soft tissue lesions of the lumbo- sacrum, such as prolapse of the intervertebral disc, soft tissue neoplasia, or nerve root entrapment, are not identified; thus conventional radiographic evaluation is subject to a false-negative result

Hilar-Region Mediastinal Masses What are the two most common causes of masses in this region?

The main causes of a hilar region mediastinal mass are enlargement of the tracheobronchial lymph nodes and a mass arising from the base of the heart Enlargement of the tracheobronchial lymph nodes classically results in a soft tissue mass located dorsocaudal to the tracheal bifurcation on the lateral view. This mass usually results in cranioventral displacement of the tracheal bifurcation Enlarged tracheobronchial lymph nodes causing dorsal displacement of the tracheal bifurcation can be confused with left atrial dilation -. Both tracheobronchial lymph node enlargement and left atrial dilation can cause lateral divergence or splaying of the principal bronchi on the VD or DV view Masses arising from the base of the heart tend to be relatively inconspicuous as much of the mass is surrounded by other soft tissue structures and not air. Therefore these masses create an ill-defined mass rather than a distinct mass and may become very large before being detectable radiographically or clinically. -A heart base mass may represent a heart base tumor, right atrial tumor, or an enlarged main pulmonary artery

Uterine neoplasia is rare. What is the most common type? Dogs? Cats?

The majority are leiomyomas for dogs *By contrast, aggressive adenocarcinoma is most common in cats

Acute pyelonephritis can lead to mild renal enlargement, whereas renal size is reduced in chronic pyelonephritis. *Chronic pyelonephritis is difficult to distinguish from other chronic renal diseases, because it is characterized by small, irregularly shaped kidneys with mild pyelectasia

The mean diameter of the renal pelvis with pyelonephritis was 3.6 mm in dogs and 4.0 mm in cats.

Mediastinum What is it?

The mediastinum is the space between the two pleural sacs -It extends in the thoracic cavity from the thoracic inlet to the diaphragm The mediastinum is not a closed space. It communicates cranially with the fascial planes of the neck by way of the mediastinal structures passing through the thoracic inlet, such as the esophagus and trachea and some major vessels. Caudally, the mediastinum communicates with the retroperitoneal space through the aortic hiatus. These communications provide for the spread of mediastinal disease to the neck and retroperitoneal space, and vice versa. The mediastinum does not normally communicate with the peritoneal cavity.

Dorsal mediastinal masses

The most common cause of a dorsal mediastinal mass is enlargement of the esophagus; this enlargement can be generalized or segmental. Enlargement of the cranial aspect of the thoracic esophagus, as from a vascular ring anomaly, typically causes a craniodorsal mediastinal mass with ventral displacement of the trachea in the lateral view.

What radiographic signs of a dipahragmatic hernia might once expect?

The most consistent radiographic signs of traumatic dia- phragmatic hernia are 1. Abdominal viscera within the thorax 2. Displacement of abdominal or thoracic organs, or both; 3. partial or complete loss of the thoracic diaphragmatic surface outline 4. asymmetry or altered slope to the diaphragm on the lateral projection 5. and the presence of pleural fluid *Herniated solid abdominal parenchymal organs are difficult to distinguish from localized pleural fluid, pulmonary opacity, or both.

Nasal passages and paranasal sinuses

The nasal passage extends caudally from the external nares to the cribriform plate and nasopharynx. The cribriform plate is a sieve-like partition between the olfactory bulb and nasal passage. The nasal passage is divided in half by the nasal septum and is filled with thinly scrolled conchae The vomer bone is unpaired and forms the caudoventral bony part of the nasal septum. The cartilaginous nasal septum cannot be seen in radiographs Both dogs and cats have frontal sinuses (see Fig. 11.1), lateral maxillary recesses, and small sphenoidal sinuses. These are named for the bones in which they are located.

Radiographic appearance of the oesophagus

The normal esophagus is usually empty and rarely evident on thoracic radiographs in cats and dogs This is because of its location within the mediastinum and silhouetting with adjacent muscles and mediastinal structures. On left lateral thoracic radiographs, the normal caudal thoracic esophagus sometimes contains a small amount of fluid and can be visualized as a faint tubular soft tissue opacity between the descending aorta and caudal vena cava Gas can accumulate in animals that are excited, dyspnoeic or sedated (usually a small amount just cranial to the tracheal bifurcation) General anesthesia or aerophagia may even lead to severe dilation of the esophagus, which can appear identical to pathologic megaesophagus (this resolves post GA)

Anatomy of the prostate gland

The normal prostate gland surrounds the most proximal aspect of the urethra and lies ventral to the rectum and caudal to the urinary bladder, typically within the pelvic canal. *not usually seen radiographically unless enlarged

Opacity only indicating an alveolar pattern

The only other thing that could cause an increased opacity like this would be a interstitial mass -we know its not as a mass as its not sharply demarcated

Neoplasia ovaries

The ovaries are located within the peritoneum and are suspended by the ovarian ligaments. When the ovary enlarges, these ligaments elongate, allowing the enlarged ovary to gravitate ventrally along the adjacent body wall

What are the radiographic signs of a UAP? What view is it best seen on?

The primary radiographic finding consists of a radiolucent line separating the anconeal process from the olecranon in dogs older than 150 days -This lucent line can be sharply defined, or it may appear irregular and of variable width. It is best seen on a flexed lateral view of the elbow joint -The flexed lateral view displaces the medial epicondyle and epicondylar physis away from the anconeus, thereby decreasing the possibility that an overlying epicondylar physeal line may be confused with an ununited anconeal process margin.

Elbow OA/Djd is often worse on the medial side What is the landmark to distinguish the medial and lateral area in a cranial caudal elbow view that is non labelled

The radial head is lateral The radius located medially at the carpus but laterally at the elbow You can see the medial coronoid process of the ulna quite well in the normal view Middle view = OA/DJD changes are most severe on the medial side of the joint Far right view = again OA/DJD changes are most severe on the medial side (see osteophyte formation on the mcp)

Kidney U/S Can the renal pelvis nromally be seen?

The renal cortex in most patients is hypoechoic to isoechoic to the liver and spleen, although dogs and cats without evidence of renal disease may have a renal cortex that is hyperechoic to liver. In cats, cortical hyperechogenicity can be seen in association with fat deposition The normal medulla is hypoechoic, creating a well-defined transition to the cortex. The interlobar vessels and pelvic diverticula give the renal medulla a lobulated appearance. The arcuate vessels are seen at the corticomedullary junction as short, hyperechoic parallel lines that may produce a distal shadow, not to be confused with renal mineralization. The renal pelvis is normally collapsed, but a smoothly margined, thin rim of fluid of up to 2 mm in diameter can be seen in normal animals, especially when using high-resolution transducer Normal ureters cannot be seen

What about the sacrum? What does it articulate with?

The sacrum is also much different morphologically than a prototypical vertebra It is 3 fused vertebrae It articulates cranially with the seventh lumbar vertebra, caudally with the first caudal vertebra, and laterally with the ilium on each side, forming the sacroiliac joints. The spinous processes of the sacrum are fused, making up the median sacral crest, and the sacral wing has a large facet for the sacroiliac articulation. Multiple foramina are present dorsally and along the pelvic surface of the sacrum, allowing for passage of spinal nerves and blood vessels.

Oblique views What surface are these intended to highlight?

They are intended to project different edges of a joint or region Important edge lesions can be overlooked unless they are projected tangentially where they will be visible at the periphery of the part (this is maximised in an oblique view) The point of entrance of the primary x-ray beam is typically moved 30 to 45 degrees medial and 30 to 45 degrees lateral to the point of entrance used for a craniocaudal (dorsopalmar, dorsoplantar) view

Atlantoaxial subluxation

The spinous processes of C1 and C2 normally are in close proximity, and the dorsal laminae are nearly parallel, on the lateral projection. This normal relationship is important in recognizing atlantoaxial subluxation. In atlantoaxial subluxation, the axis (C2) is displaced dorsally with respect to the atlas (C1), causing extradural compression of the spinal cord Can be congenital (more common in toy breeds e.g. yorkie) or trauma Clinical signs include -pain -cervical neuropathy

Intussusceptions on U/S

The telescoping effect results in a concentric ring appearance when viewed in the transverse plane and a multilinear pattern when viewed in the longitudinal plane. A hyperechoic region is typically noted mildly eccentrically positioned within the concentric or linear pattern, caused by mesenteric fat pulled into the intussuscipiens. The shape of this hyperechoic material may be round or semilunar.

Under vs overexposure

The top L image = perfect R top image = underexposed (grainy) - difficult to see.. Bottom image = overexposed - prepuce is gone

Again..if we looked at the bone lesions alone we could class HOD as radiographically aggressive

The transition zone between the normal and abnormal bone is indistinct in the acute lesions and the margin of the lesions in later forms is irregular. Therefore, these lesions cannot be distinguished from hematogenous osteomyelitis; and as noted earlier, suppurative inflammation has been identified in some patients. As with panosteitis, the scenario of these lesions developing in a young dog of one of the high-risk breeds leads to a diagnosis of hypertrophic osteodystrophy. But, if the lesions do not resolve spontaneously as expected, blood cultures or a culture of an aspirate from the lesion would be justified to rule out an infection.

The transverse colon?

The transverse colon lies adjacent to the greater curvature of the stomach, left lobe of the pancreas, liver, small intestine, and root of the mesentery.

Mediastinal lymph nodes

The two most common causes of enlargement are -Lymphoma -Mycotic infections Things that you feel should cause enlargement but don't tend to.. Primary lung tumor Metastatic lung tumor Bacterial pneumonia Pyothorax Rib tumors

Temporomandibular joint and tympanic bullae

The tympanic bullae (see Fig. 11.1) form the ventral part of the temporal bone. These air-filled cavities of the middle ear communicate with the nasopharynx via the auditory tube. The temporomandibular joint (TMJ) is a condylar joint. -The temporal portion consists of the zygomatic process of the squamous temporal bone The mandibular aspect of the joint includes the condyloid process, which articulates with the mandibular fossa

Multiple nodules Which is the easiest place to look for this?

They are often more conspicuous superimposed on the heart or liver Can unfortunately be easy to overlook one small nodule

Pleural anatomy

There are two distinct pleural sacs, one on each side of the thoracic cavity. Each pleural sac has parietal (mediastinal, diaphragmatic, costal) and visceral components (visceral lines the lungs). *mediastinal parietal pleura forms the boundaries of the medi- astinal space, dividing the thorax into left and right halves

Give 3 differentials for this appearance

There is a soft tissue mass in the caudodorsal aspect of the thorax between the aorta and caudal vena cava with its caudal border superimposed with the diaphragm. Based on this appearance, the considerations are esophageal foreign body, esophageal mass, paraesophageal hernia, or pulmonary mass. B, Ventrodorsal (VD) radiograph of the same dog. The mass is on the midline (white arrows), making a pulmonary mass unlikely. Endoscopy was performed, and a hard, cartilaginous foreign body was removed.

How do i get the frontal sinus view?

There is a table in the textbook or other views in chapter 9 for additional views

Gallbladder Abnormal wall thickness, luminal contents, obstruction, and neoplastic disease may be diagnosed on ultrasound examination. What are causes of increased wall thickenss?

Thickening of the wall is non specific and can be due to 1. neoplasia 2. Local inflammation aka cholecystitis from.. * cholangiohepatitis *biliary stasis *irritation from choleliths Emphysematous cystitis, usually associated with a septic process and gas-forming bacteria, results in intraluminal echogenic foci and reverberation artifact 3. Systemic disease -e.g. RSCHF can cause oedema of the gallbladder wall (has a layered appearance to the wall) -anaphylaxis also causes oedema -portal hypertension also causes oedema -sepsis and hypoproteinaemia can also cause oedema 4. Hyperplastic gallbladder wall epithelium, cystic accumulations of mucus, and papillary projections create the appearance of sessile or polypoid masses along an irregularly thickened gallbladder wall Gallbladder thickening may be permanent because of inflammation and fibrosis despite resolution of the underlying disease process

Tracheal foreign bodies What is the most common location?

Think a tooth, stone, kibble, bone Aspirated foreign bodies are most often lodged at the carina

Hypervitaminosis

Think all liver diets..

Simultaneous Pleural and Peritoneal Fluid List the two most likely ddx for this

Thirty-two of 48 dogs with simultaneous peritoneal and pleural fluid had either neoplastic or cardiovascular disease. Simultaneous pleural and peritoneal fluid is an indicator of severe disease with poor prognosis

NOT AN AIR BRONCHOGRAM

This bronchus is outlined by vessels and this is normal

Oesophageal dilation

This can be 1. Focal 2. Generalized It can also be 1. Functional (usually results in generalized disease) 2. Mechanical

Generalized Cardiomegaly

This can result from combinations of chambers enlarged or all four chambers Dilated cardiomyopathy is a common cause of generalized cardiomegaly

What are the black and white arrows?

This dog has mild pleural effusion Black lines = pleural fissure lines White= costal cartilages Care as sometimes this is misinterpreted costal cartilages are larger and more linear, and they can be followed laterally to attach to a rib.

Kissing lesion .

This is an elbow with a fractured medial coronoid process (you can't see this directly but there is an osteophyte) You can also see just under the cursor there is a lucency which is the kissing lesion (eroded cartilage) You cant tell this apart from an OCD lesion of the medial humerual condyle

Gastric Dilation Volvulus

This is differentiated from acute gastric dilation by the presence of gastric malpositioning in addition to pathologic gas distension of the stomach. The radiographic appearance of the stomach varies depending on the type and degree of rotation and the amount of distention. As the stomach dilates, the fundus and greater curvature rotate clockwise, when viewed from caudal to cranial, to lie along the ventral abdominal wall. The pylorus therefore shifts dorsally, cranially, and to the left, and the body of the stomach shifts toward the right. Because of the attachments of the proximal extremity of the spleen to the stomach, the spleen often follows the greater curvature toward the right. The major radiographic feature of gastric volvulus is gas and fluid distention of the stomach. Additionally, the pylorus is usually displaced dorsally and to the left, unless a 360-degree rotation of the stomach is present. Thus, radiographic determination of the location of the pylorus is the key differentiating feature between gastric dilation and gastric volvulus. Lateral views are usually of the most value to identify the location of the pylorus. When filled with gas, the pyloric portion of the stomach appears more tubular and narrower than the rest of the stomach. Although the stomach is filled primarily with gas, it usually contains enough fluid so that the pyloric portion may fill with fluid in one lateral view and thus not be seen. With the pylorus shifted to the left and with the patient in left lateral recumbency, fluid in the stomach fills the pylorus and gas fills the rest of the stomach. With the patient in right lateral recumbency, gas fills the pyloric portion and fluid shifts to the fundus or body of the stomach. This gas distribution is opposite to what is normally expected Gastric volvulus is often detectable in a right lateral radiograph *Gastric volvulus may also be present without severe gastric distention Compartmentalization is a term that refers to the radiographic appearance of soft tissue bands that project into or across the gas-filled lumen of the rotated stomach. These soft tissue bands result from folding of the stomach on itself as the folded wall projects into the lumen and is outlined by gas within the lumen. https://www.youtube.com/watch?v=JaAN-6FrPTM&ab_channel=PattersonVeterinary

Partial obstructions may also be difficult to detect..

This is particularly true when the partial obstruction is of short duration and in the proximal duodenum. Longstanding partial distal obstructions result in accumulation of opaque granular material proximal to the site of obstruction. This is caused by desiccation of ingesta that becomes trapped proximal to the obstruction. The desiccated material often has the appearance of feces, and the identification of this fecal-like material in the small rather than large bowel is a reliable sign of partial distal small bowel obstruction. This appearance has been referred to as the gravel sign If a bowel obstruction is complete, the small intestine distal to the obstruction is likely to be empty.

Gastric Bleeding Can this be seen on X-rays?

This is suspected when the patient is vomiting blood containing ingesta or fluid or when digested blood is present in the feces. Survey radiographs will frequently not reveal the cause U/S or contrast radiographs may reveal gastric thickening/mass or an ulcer but if nothing is found further imaging may be needed

Fragmented medial coronoid process? Signs show up as early as 4-6 months Hard to detect on X-rays (he said basically impossible to assess accurately) Very common

This is the most common cause of elbow dysplasia Primary affects larger breed dogs and mainly males Radiographic visualization of the coronoid fragment is usually not possible because of superimposition of the medial coronoid process on the radius, superimposition of proliferative new bone from degenerative joint disease on the coronoid fragment, or failure of the x-ray beam to strike the fragment plane in a parallel fashion In addition, coronoid fragments that consist mostly of cartilage or that are still partially attached to the ulna cannot be seen radiographically. Fracture or fatigue fracture is a better term then fragmented

Alveolar lung pattern List 4 things that can fill the alveoli to result in this pattern

This is when the alveoli contain something other than air Lung size is usually unchanged 1. Blood 2. Pus 3. Oedema 4. Cells (not common) OR Alveoli contain no or reduced air but are normal -Atelectasis (lung collapse)

Spontaneous Capital Physeal Fracture of Cats

This occurs without associated trauma! -Commonly male cats that had early age neutering. Obesity is another factor -Usually approximately 2 years of age Fractures are frequently bilateral The primary radiographic abnormalities include varying degrees of malalignment of the capital epiphysis, femoral head and neck osteolysis, and regional sclerosis

Positive-contrast retrograde urethrogram What is the colliculus seminalis..?

This procedure allows evaluation of the urethra itself and the position of the urethra in relation to suspected prostatic disease. The junction of the prostatic urethra with the neck of the urinary bladder should be evaluated carefully. Small filling defects or mucosal ulcers that may be early lesions of transitional cell carcinoma may be detected. These small lesions may not be detected on a cystogram or even ultrasonography because they are obscured by the *internal urethral sphincter*, which is actually encircled by the prostate gland.

Obesity or brachycephalic dogs

This should not be confused with displacement from a mass, such as from a heart base tumor

True vaginal prolapse is rare in the bitch..why would it occur?

This usually occurs near or after parturition but may also be associated with tumors or trauma. -mostly in young, intact, large-breed dogs in proestrus or estrus.

As in the liver, splenic ultrasound is sensitive but not specific. Lots of overlap between appearance with diseases True cut biopsies with what have been used?

Tissue samples are necessary for a more definitive diagnosis. Although diagnosis of diffuse splenic disease (e.g., lymphosarcoma or extramedullary hematopoiesis) may be achieved with needle aspiration, cavitated mass lesions (e.g., hemangiosarcoma or hematoma) may be diagnosed more accurately by splenectomy and histopathologic evaluation. Tru-Cut biopsies of the spleen using 18 g needles have been reported with minimal complications. 203

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To be obstructed, you want to see foreign material extend into the pylorus In this case the pylorus is gas filled (no FB seen) - this is the green arrow So in this case we have a puppy with foreign material in the stomach, but not currently obstructing.

Lateral spine Which one is rotated? Which is straight?

Top = rotated -the transverse processes are not lined up "the nike tick" - should only see one Bottom = straight -the wings of the illium line up

Tracheal Collapse What area does it occur in?

Tracheal and bronchial chondromalacia and collapse are seen commonly in middle-aged and older small- and toy-breed dogs. Affected dogs typically have chronic cough, although signs of upper respiratory obstruction can occur in severely affected patients. Collapse can be static or dynamic; in the latter, severity depends on the phase of the respiratory cycle Collapse can occur anywhere from the midcervical region to involving the entire thoracic trachea Intrathoracic collapse is usually more pronounced on expiration, whereas collapse in the cervical and thoracic inlet regions is more pronounced on inspiration. The sudden increase in intrathoracic pressure during coughing exacerbates intrathoracic tracheal collapse. The chronic cough caused by tracheal collapse contributes to a cycle of chronic inflammation, which in turn worsens chondromalacia Cervical tracheal collapse can lead to laryngeal collapse and upper respiratory edema through chronic inflammation and increased inspiratory pressure. Pharyngeal collapse can also be associated with tracheal and bronchial collapse and can sometimes explain persistent increased respiratory effort following stenting. Location and extent of maximal collapse is often evalu- ated using the following scale: 25%, 50%, 75%, and 90% to 100% reduction of tracheal diameter. 25% or less is WNL *rare in the cat. usually 2ndry to URT obstruction

Tracheal rupture/avulsion What signs might I see?

Tracheal rupture may be caused by endotracheal intubation, particularly during dental prophylaxis in cats, a penetrating wound (dog bites particularly), blunt trauma, or a foreign body. Radiographic signs of secondary focal or generalized cervical and thoracic soft tissue emphysema and pneumomediastinum are present and more easily seen than the actual tracheal rupture, which is seen only rarely Tracheal avulsion in cats occurs following blunt trauma with severe hyperextension of the head and neck. Paradoxically, patients are often presented 1 to 3 weeks following the traumatic event, and signs of pneumomediastinum and soft tissue emphysema have resolved.

What is the circle?

Tracheobronchial lymph node enlargement (hazy more intense opacity here)

Thorax Principles of interpretation What triangle am i looking at to see if the patient was breathing in enough?

Try and take the X-ray on peak inspiration -overweight patients may have reduced ventilatory capacity leading to reduced lung volume and a false impression of increased lung opacity

Bladder neoplasia. Which is most common?

Transitional cell carcinoma -single or multiple masses can be present Unfortunately, the sonographic appearance of polypoid cystitis, adherent blood clots, and mural hematomas is similar to that of urinary bladder neoplasia.

What type of fracture is this?

Transverse diaphyseal fracture of the ulna and radius

Post soda

Triangular opacity (sharply marginated)suspicious *there is also a frothy appearance - this is normal after giving sprite

Vascular ring anomalies What is this?

Under normal conditions, the aorta is derived from the left fourth aortic arch while the right fourth aortic arch typically regresses. Anomalous development of the aortic arches can lead to secondary extrinsic esophageal compression. The compression results in esophageal dilation cranial to the base of the heart.

Chart of bone lesions

Unfortunately, bone is very limited in its response to injury. There will be either more or less bone than normal, a periosteal response will be either present or not, and the soft tissues will be either involved or not. Thus, the distribution within the skeleton and the assessment of the patient signalment become extremely important factors in formulating a reasonable dif- ferential diagnosis and for formulating a plan

Cholangitis/cholangiohepatitis complex is an important biliary disease in cats. What biliary changes may we see?

Ultrasound changes may include 1. Thickened gallbladder wall often with irregular mucosa 2. Intraluminal gallbladder or bile duct sludge 3. Choleliths/choledocholiths 4. thickened, tortuous, and sometimes dilated bile ducts No ultrasound changes are present in some cats with cholangitis/ cholangiohepatitis.

Abnormal Sonographic Appearance of the Liver

Ultrasound is helpful in differentiating between diffuse and focal hepatic disease in patients with hepatomegaly and/or elevated liver enzymes. *Diffuse hepatic disease may cause no change in the ultrasound appearance of the liver. However, changes in hepatic echogenicity, increase or decrease in size, and irregular or rounded margins point to diffuse hepatopathy. -A hyperechoic liver is identified by comparison with the echogenicity of an adjacent organ, such as liver being hyperechoic to renal cortex, or isoechoic or hyperechoic to spleen

What is an Antegrade US guided pyelography?

Ultrasound-guided injection of contrast medium into the renal pelvis The main indication for this procedure is suspected ureteral obstruction. Some degree of renal pelvis distention (at least 5 mm) has to be present to perform the procedure.

Temporomandibular Joint Dysplasia

Uncommon Results in open mouth jaw locking e.g. after yawning basset hounds at risk Need CT to surgically plan

Rib Infection

Uncommon - usually secondary to trauma. Sternebral infection is also uncommon Unable to differentiate from neoplasia on X-rays

What is a Peritoneopericardial diaphragmatic hernia?

Uncommon congenital defect A ventral communication between the abdomen and pericardial sac is present -this means the stomach or other abdominal organs can be in the pericardial sac Classic radiographic findings are -marked enlargement of the cardiac silhouette -lack of visualisation of a distinct definition between the caudoventral aspect of the cardiac silhouette and the diaphragm

CT and MRI are both tomographic What does this mean?

We are looking at cross sectional slices

Dental Webinar

Up to 45% of disease in only in the subgingival domain

A pointed apex with an elongated urinary bladder may occur with a persistent...

Urachal ligamanet

Appearance of difference calculi on bladder X-rays Who is non radiopaque? Whos is spikey?

Urate and cystine Calcium oxalate (can also be smooth though)

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Urethral fistulas can be demonstrated as extraluminal extension of contrast medium to another hollow organ (e.g., the colon or vagina) In young patients, they are most often congenital anomalies but may also be acquired as a sequel to urethral rupture, for example.

Clinical signs of prostatic disease List a less common sign

Urinary: Stranguria, hematuria, and pyuria Defecation: dyschezia with small or ribbonlike stools, constipation A less common sign of prostate gland disease is a pelvic limb gait abnormality. The animal may refuse to climb stairs and jump. Owners often believe the animal has developed osteoarthritis, but such animals may have severe, active septic prostatitis. The pain caused by the prostatic infection is exacerbated by walking, climbing, and jumping. Both pelvic limbs are usually affected. These animals are also usually sensitive to palpation of the caudal abdomen.

U/S of the urinary bladder

Urolithiasis, neoplasia, cystitis, urachal, and vesicoureteral junction abnormalities can be identified by using sonography. Side and grating lobe artifacts generated by the adjacent colon can give rise to an erroneous display of echogenic material in the urinary bladder lumen, and the curved urinary bladder wall can create additional echoes adjacent to the dorsal urinary bladder wall Image contrast settings should be set to high-contrast display; acoustic power and near gain should be decreased to suppress reverberation echoes generated between the transducer, the skin, and abdominal wall structures. The ureters and urethra are not typically visualized unless they become distended with urine. *Contrast radiographic techniques are superior to sonography in diagnosing congenital abnormalities of the urachus and ureters as well as urinary bladder rupture.*

Osteomyelitits What is the most common cause?

Usually a result of contamination occurring at the time of the fracture, such as an open fracture or contamination during extended surgery In general, normal callus is smooth and the periosteal reaction resulting from infection is active, or irregular. Also, clinical signs of osteomyelitis may be recognized before radiographic signs are present. These include, pain, swelling, and heat with or without a fever. In the early stages, soft tissue swelling will be the only radiographic change observed with rare instances of soft tissue emphysema if a gas-producing organism or draining tract is present. Radiographs made 7 to 10 days after the onset of infection may have early mineralizing periosteal changes. If the infection continues, signs of an aggressive bone lesion (such as, bone lysis) and a more extensive active periosteal reaction will be present.

Fracture and luxation of vertebrae

Usually due to significant trauma e.g. HBC, falling Many vertebral fractures and luxations occur at regional junctions, for example, atlantooc- cipital, atlantoaxial, cervicothoracic, thoracolumbar, and so forth. Radiographic features of vertebral fractures include asymmetry, specifically of the articular processes and endplates; displacement of a vertebra with respect to adjoining vertebrae (malalignment); and comminution of the endplate or body. An incomplete vertebral fracture is difficult to detect radiographically, and malalignment may be the only abnor- mality found.

Retained Cartilage Core Who? Where?

Usually occurs in the distal ulnar metaphysis of large breed dogs May cause ALD but may also be incidental Typically see the lesion as a cone shape

Uterine torsion Who does this happen to?

Uterine torsion is a rare complication of pregnancy in the bitch and occurs rarely in association with pyometra, hematometra, and endometrial polyps. It is associated with a high mortality rate because of peritonitis and endotoxemia. The radiographic and sonographic appearance is not specific, and in all instances, the uterus will already be enlarged in association with pregnancy or pyometra. Correlation with clinical signs is important. In pregnancy, uterine torsion has been associated with dystocia. In most instances, the diagnosis will be made surgically.

Poll7 Cut or not?

V+ dog

Detecting a change in kidney size is helpful for classification of renal diseases into acute or chronic. What is the best view to measure this on? What is normal for a dog? cat?

VD - because there is no overlap of the kidneys, and magnification of both kidneys is equal. Renal length in normal dogs ranges between 2.5 and 3.5 times the length of L2. In cats, the normal renal length has been measured to be 2.4 to 3.0 times the length of L2. Older cats without signs of renal disease can have smaller kidneys (1.9 to 2.6 times the length of L2); however, it is difficult to know whether subclinical renal disease may have been present in these cats Normal kidney size in cats ranges between 3.0 and 4.3 cm

What is the Ureterovesicular junction?

Where the ureter meets the bladder -can be visualized in normal dogs as small convex structures on the dorsal part of the urinary bladder. -Identifying a ureteral jet in the urinary bladder confirms a normal ureterovesicular junction Ureteral ectopia can be diagnosed with ultrasound by identifying dilated ureters coursing past the urinary bladder neck. Concurrent renal pyelectasia and hydroureter may be present

Several diffuse hepatopathies can potentially result in either a diffusely hyperechoic liver, or a mottled appearance.. List the two most common

Vacuolar hepatopathies - this includes 1. Hepatic lipidosis 2. Steroid hepatopathy

What does chronic hepatitis look like on U/S?

Variable!! -*May* have increased echogenicity due to parenchymal fibrosis. -May have a mottled parenchymal echogenicity -Mayhave diffuse nodular appearance -May also be hyperechoic secondary to hepatic lipidosis -Can also be hypoechoic Size can be variable Hepatic cirrhosis typically results in a small, irregular, hyperechoic liver

What are radiographic features of gastric neoplasia?

Varies depending on the size and nature of the neoplasia. -The major radiographic feature of gastric neoplasia is that of a mass lesion that projects into the gastric lumen, creating a filling defect within the contrast medium. -Larger masses may lead to an outflow obstruction -Diffuse lesions may not produce a filling defect

Neoplasia of the spine

Vertebrae are commonly affected by neoplasia -metastatic more likely then primary Radiographic signs of vertebral neoplasia are nonspecific and typical of an aggressive bone response and include bone lysis, new bone production, and pathologic fracture

3. Transitional vertebrae

Vertebrae that have characteristics of two different anatomic divisions are known as transitional vertebrae. These anomalies usually involve the vertebral arch rather than the body and occur at cervicothoracic, thoracolumbar, and lumbosacral junctions. The main clinical significance of transitional vertebral anomalies relates to the use of the most caudal ribs as a landmark to identify a site of spinal decompressive surgery. However if the LS vertebrae is transitional there is an increased risk of LS disease and nerve compression

What is vertebral physitis?

Vertebral physitis occurs in young dogs, and initial radio- graphic signs include osteolysis of the physeal zone of the affected vertebrae with sparing of the endplates. With progression, there is collapse of the cranial or caudal aspect of the vertebral body and endplate sclerosis. Sepsis is the proposed cause because of hematogenous localization in the slow-flowing capillaries of the vertebral physis. Acinetobacter and Enterococci species have been isolated from vertebral biopsy material.

Case study Teddy

Very real concern for fracturing the jaw Toy breed dogs are classic for having these long roots He finds talking to clients about dentals much easier having X-rays

Persistent deciduous teeth

We know how frustrating these teeth can be and how long the roots can be I find X-rays particularly useful in these cases where the deciduous tooth has been in situ for a reasonable amount of time after the adult canine has erupted They are useful to determine how much of the root structure is still in place around the deciduous tooth In order for these teeth to exfoliate normally the process is essentially disintegration or resorption of the root structure So if we take an X-ray pre extraction we may determine that it doesn't matter so much if we pull the tooth and its roughened on the edge - we can be confident its not going to be a problem later for this dog See also how the apex is open in the adult canine for this dog - that tends to close at 8-11 months typically -also wide pulp cavity and little dentine in these immature teeth

Unstructured interstitial disease What could cause this?

We mean infiltration of the interstitium of the lung with cells or fluid Tends to be diffuse/generalised Technical factors are common -Obese patient (soft tissue in the thoracic wall will be projected onto the thorax) -Underexposed X-ray -Exhalation (less air in the lung which will emphasise the interstitium) Patient factors are less common -Aging changes -Inflammatory processes e.g. fungal infx -Infiltrative processes -Vasogenic factors e.g. pulmonary oedema (not common)

IBD

When neoplasia, infection, and food-responsive disease are excluded from the broad category of infiltrative bowel disease, the general term idiopathic IBD is used. In both the canine and the feline patient, IBD refers to a group of disorders of undetermined etiology that cause chronic (>3 weeks) vomiting and/or diarrhea and have various populations of inflammatory cells in the bowel wall layers. The most common of these is a lymphocytic-plasmacytic enteritis

Functional Ileus List the 3 most common causes

When peristaltic contractions of bowel cease because of vascular or neuromuscular abnormalities, the lumen dilates and remains patent. More common diseases that cause ileus are -Viral enteritis (e.g. parvovirus) -Peritonitits -chronic mechanical obstruction (this can eventually lead to functional ileus as the bowel becomes fatigued) Less common -Strangulation of the intestine through a hernia (vascular compromise) -Mesenteric torsion *Mesenteric volvulus results in occlusion of the cranial mesenteric artery. The reduced blood supply leads to ischemic necrosis, gastrointestinal toxin release, shock, and subsequent paralytic ileus. The initiating event for volvulus typically is not known. -Dysautonomia

Patient positioning can change the position of the trachea

When the patient's head is ventroflexed, focal dorsal displacement of the trachea can mimic a cranial mediastinal mass Conversely, extreme extension of the neck can cause tracheal narrowing.

5 month old puppy ate nylabone v+

Where is the pylorus on the L lateral?

Radiographic Signs of Major Vessel Enlargement 2. Aorta

Widening of the precardiac mediastinum, as seen in the VD or DV views, can indicate dilation of the aortic arch. In normal dogs, the width of the mediastinum in VD radiographs should be less than approximately twice the thickness of the spine. A focal bulge in the descending aorta in VD or DV views can be seen in patients with aortic stenosis and patent ductus arteriosus. In lateral views, an enlarged aortic arch can create increased mass at the cranial aspect of the cardiac silhouette

Other potential radiographic signs

With generalized hepatomegaly you may see caudal displacement of the stomach, right kidney, transverse colon, and cranial duodenal flexure The pylorus may be dorsally displaced On VD views, the enlarged liver will cause displacement of the body and pyloric portion of the stomach caudally, and to the left

What view can help detect talus defects?

With osteochondrosis of the lateral trochlea of the talus, the superimposed calcaneus may obscure the lesion in the dorsoplantar view. In this instance, a dorsolateral/plantaromedial oblique, or a flexed dorsoplantar, view can be acquired to provide an unobstructed view of the lesion.

What about dogs with bent legs? (you can't get a craniocaudal of both the carpus and elbow concurrently as the joints twist!)

You need to take multiple X-rays as they have done here - one with the elbow in a cranial caudal position (left view) and one with the carpus in a cranial caudal position (right view)

Panosteitis Age of onset/signalment Where?

Young, large breed dogs Males 4x more affected than females Age of onset tends to be 5 months to 12 months Self limiting disease of long bones. Eventaully fills in with normal bone Panosteitis lesions may be solitary, affect multiple sites in a single bone, or be multifocal in multiple bones. Although the lesions can affect any part of the diaphysis of a long bone, they often originate and are most pronounced near the nutrient foramen. Bone involvement is often sequential, and the disease may be protracted over several months, with lesions resolving in some bones while developing in others. Panosteitits is a silly name as inflammation has not be proven

Intra articular calcified bodies AKA

joint mice -occasionally observed in cats and dogs Articular calcified bodies usually fall into three fairly distinct categories: (1) avulsed fragments of articular or periarticular bone (2) osteochondral components of a disintegrating joint surface, or (3) small synovial osteochondromas Sesamoid bones may be mistaken as mice.

m22

mechanical obstruction caused by a peach pit. There are a few gas-distended loops of jejunum, and some distended segments also contain fluid (black arrows).

Aortic Stenosis

• Enlargement of the aortic arch from turbulent flow, appearing as widening of the precardiac mediastinum • Elongation of the left ventricle from hypertrophy • Left atrial dilation if secondary mitral valve dysfunction develops • Normal pulmonary vessels unless secondary mitral valve dysfunction develops, leading to pulmonary venous hypertension • Radiographs may be normal

Mitral valve disease What radiographic signs may we expect to see?

• Left atrial enlargement, attributable to dilation caused by volume overload from mitral valve regurgitation • Left ventricular enlargement, from dilation caused by volume overload because not as much blood is ejected from the left ventricle with each systole • Distended pulmonary veins if venous hypertension has developed • Distended pulmonary arteries if pulmonary arterial hypertension or fluid retention is present • Pulmonary edema (left-sided heart failure)

Tricuspid Dysplasia

• Right atrial enlargement from pressure and volume overload is seen. • Pulmonary vessels are usually normal but may become small if cardiac output decreases from the right ventricle.

Heartworm.

• Right ventricular hypertrophy in response to pulmonary hypertension • Dilation of the main pulmonary artery caused by turbulent blood flow and pulmonary hypertension and possibly the physical presence of heartworms • Parenchymal pulmonary artery enlargement and/or tortuosity from pulmonary hypertension and/or loss in laminar blood flow • Peripheral focal or multifocal alveolar pulmonary pattern from pulmonary thromboembolism caused by dead adult worm fragments or secondary allergic pneumonitis, which may only present as a generalized, unstructured interstitial pulmonary pattern opacity • Hepatomegaly, ascites, and occasionally pleural effusion caused by right-sided heart failure

Pericardial Effusion

• There is a large round (globoid) cardiac silhouette in both lateral and VD or DV views if the effusion is severe enough. With mild or moderate amounts of fluid, the cardiac silhouette will not be generally round. • The margin of cardiac silhouette may appear distinct as a result of little, if any, motion caused by cardiac contractions. • In severely affected patients, the margins of the hugely enlarged cardiac silhouette may touch the thoracic wall bilaterally. • Signs of right heart failure (enlarged caudal vena cava, hepatomegaly, ascites, and occasionally pleural effusion) may be present if pericardial tamponade is severe enough to prevent diastolic filling of the right atrium and ventricle. • Small to moderate volumes of pericardial effusion often do not have the previously described radiographic signs and can go undetected without echocardiography.