Intro to Radiology
what are the 3 decubitus positions?
-ventral -dorsal -left lateral
callus formation
Bone matrix appears a few days after injury, called "soft callus", not visible radiographically As callus becomes more dense it becomes more visible on radiograph
What does any particular radiographic image reflect on?
Both the density (atomic number) and thickness of the structures in the path of the x-ray beam at that anatomic position. Many overlapping structures can also contribute to a particular summation of densities.
Why do the Shades of Gray are important?
In order to fully comprehend the visual information in radiographic images, you must distinguish among these radiographic densities, often referred to as shades of gray.
oblique (erect or recumbent) position
•the body is rotated so that the MSP is at an angle •Exact position is indicated by the surface closest to the IR and the angle of rotation •May be erect or recumbent •abbreviations: RPO, LPO, RAO, LAO
evidence of lateral projection o elbow
-90o degrees flexion -olecranon process of ulna is in profile
factors that affect fracture healing categories
-Accelerate Fx. Healing -Delay Fx. Healing
wrist fractures
-Colles -Smith
5 Radiographic Densities
-Metal -Calcium (Bone) -Soft Tissue (Water) -Fat -Air (Gas)
What does Radiology Requisition include?
-Patient history -Findings on physical exam -Relevant laboratory findings -Clinical diagnosis
2 Descriptive terms
-Radiopaque -Radiolucent
reduction fracture
-Return fractured bone to proper alignment so bone can heal properly -To decrease pain and to preserve function
the Body Planes include:
-Sagittal -Coronal -Oblique -Horizontal (transverse or axial)
Compartment syndrome
-Severe swelling resulting in decreased blood supply can cause the muscles around the fracture to die -Bad osmotic pressure lets blood out instead of across damaged muscle
ankle injuries
-Trimalleolar -Bimalleolar
What are some of the directional terms?
-anterior/posterior -cephalic, superior, cranial/ inferior, caudal, caudad -lateral/medial -proximal/distal
how fractures can be described?
-clinical distinction -extent -type -direction of fracture line -location
how the 5 radiographic densities are helpful?
-clue us to composition of abnormality -may tell us where the abnormality is located
What are the 4 basic sections of an ideal radiology report?
-demographics -clinical information -descriptive information -diagnostic conclusion (Impression)
disruption of joints
-dislocation -subluxation
what are the abnormalities of position?
-displacement -alignment -angulation -distraction -overriding or shortening
distal humerus (supracondylar fracture)
-elbow joint effusion or hemarthrosis, which is associated with elbow fracture, is indicated by the presence of displaced periarticular fat pads on lateral radiographs
evidence for PA projection of left hand
-equal concavities of each side of the metacarpals and each phalanges -equal soft tissue portion on each side of the phalanges -equal distance between metacarpals 1-5 -No superimposition distal of radius and ulna
evidence of PA projection of wrist
-equal destination between proximal spaces -near superimposition of the distal radius and ulna with slight no superimposition of carpal bones
What is the Anatomic Position?
-erect -face forward -feet together -arms at sides with palms forward
fracture signs or descriptors include
-fat pad signs -ring bone rule -pathologic fracture -impacted fracture -avulsion fracture -fractures without significant trauma
importance of 5 radiographic densities:
-fundamental to understanding -conventional radiographs -helps tell location of disease -helps tell what they may be
fractures in children
-greenstick -Torus -Salter-Harris Classification
fixation fracture
-method of maintaining position after reduction -Preserve blood supply to soft tissue and bone
sufficient bone
-normal bone weekend by chronic repetitive stress -fatigue results from numerous micro fractures
insufficient bone
-not enough bone (osteoporosis) -insufficiency fracture
ventral decubitus position
-patient is prone & a horizontal beam is used
dorsal decubitus position
-patient is supine & a horizontal beam is used
left lateral decubitus position
-patient lying on the left lateral side & a horizontal beam is used
fracture management
-reduction -fixation
describe a fracture by its location
-relationship of fragments to each other -presence of special features -presence of associated abnormalities
fractures with specific names include
-scaphoid -colles -boxers -Bimallolar and Trimaleolar
evidence of Fan lateral projection of the hand
-superimposition of metacarpals 1-5 -lateral projection of the phalanges with anterior concavity of the phalanges and straight portion posteriorly -near superimposition of radius and ulna
What the 3 specific recumbent positions are?
-supine -prone -R/L lateral
evidence of AP projection of pelvis
-symmetry of ileum, sacroiliac joints, and obturator foramen
evidence of AP projection of elbow
-symmetry of medial and lateral epicondyle of the humerus -slight superimposition of proximal radius and ulna -external rotation position
evidence of PA oblique projection of the left hand
-unequal concavities of the phalanges and metacarpals -unequal distance and overlap of metacarpals 1-5 -more superimposition of that radius and ulna
fracture healing requirements
-viability of fragments (intact blood supply) -mechanical rest (this can be achieved by not moving, external immobilization (e.g. cast) or internal fixation) -absence of infection
how many fat stripes are in wrist?
2
what does simple extend fracture mean?
2 fragments
Growth abnormalities
A fracture through an open physis, or growth plate, could result in premature partial or complete closure of the physis; Part or all of a bone will stop growing unnaturally early
What does Orthogonal projection mean?
A radiographic projection obtained 90 degrees to the original projection. It forms the basic requirements of a radiographic series.
Structures with higher atomic numbers, such as bone, absorb ____ of the xray beam than structures with lower atomic numbers. A.more B.less C.the same amount
A.more
Malunion
Abnormal alignment
Thin body parts cast a _____ shadow on the image compared to thick body parts. A.lighter B.darker
B.darker
Body parts that are thin absorb _____ of the xray beam compared to thick body parts. A.more B.less C.the same amount
B.less
The appearance of Homer's eye can be described as A.radiopaque B.radiolucent
B.radiolucent
Structures with higher atomic numbers result in a _____ shadow on the image. A.black B.white C.gray
B.white
What shadow appearance will have at the X-ray a subject with Lower Atomic Number?
BLACK
Why do the 5 Radiographic Densities are visible?
Because of differences in the absorption and scattering of x-ray photons in their path from the x-ray source toward the digital x-ray detector.
Fat, muscle and soft tissue have similar atomic numbers and cast ____ shadows on the image. A.white B.black C.gray
C.gray
What shadow color does the Radiolucent leave?
Darker shadow
How does attenuation work?
Different tissues attenuate the the xray beam based on the average atomic number of the structures and the thickness of the tissue.
Delayed union
Extended healing time, fracture not consolidated after 3 months
Nonunion
Failure to heal, no improvement after 3 consecutive months
Post-traumatic arthritis
Fractures that extend into the joints can cause premature arthritis of a joint
Infection
Imbalance of bacteria and body's ability to cope with it when amount of necrotic tissue and contraction of bacteria are not being cleared (by surgeon or patient)
Salter-Harris Classification
Involve epiphyseal plate alone or in combination with an adjacent part of the bone
Salter-Harris type 1 through growth plate
It is a transverse fracture through the cartilage of the growth plate. Often, x-rays of a child with a type I growth plate fracture will appear normal. May perform contralateral images for comparison
supinator fat stripe
Long, thin stripe just anterior to proximal radius
They are suspected clinically if there is tenderness in the anatomic snuff box after a fall on an outstretched hand
Look for linear fracture lines on special angled views of the scaphoid (solid white arrow). Fractures across the waist of the scaphoid can lead to avascular necrosis of proximal pole of that bone
What Supine Recumbent position is?
Lying down on the back (posterior recumbent position)
What Prone Recumbent position is?
Lying face down (anterior recumbent position)
What does Radiolucent mean?
Objects that allow xrays to pass freely.
What does Radiopaque mean?
Objects that prevent xrays from passing through freely.
intramedullary nails
Operates like an internal splint that shares the load with the bone.
external fixation
Pins coming through skin interconnected by external frame -Has complications
internal fixation
Plates, screws, etc. completely within the body •Surgical intervention
why Salter-Harris classification is important?
Prognostic value -Type 1 and 2 do well -Type 4 and 5 can develop early fusion of epiphysis and shortening of the bone
Why Radiology Requisition is important?
Provides appropriate clinical information to the radiologist can make the difference between establishing a correct diagnosis and losing an important piece of information because of poor communication between medical practitioners.
Radiography
Radiography refers to the medical images that are the "shadows" projected onto a flat plane when x-rays pass through a patient. Similar to any shadow, they show the shape of the object causing the shadow.
What does Radiology Requisition mean?
Radiology requisition or "order" is an important clinical tool and is also a legal document, whether written or electronic.
what does projection mean?
Refers to the path the beam takes through part
The most accurate diagnostic tool for localizing objects or pathologies within the body is cross sectional imaging performed with computed tomography, ultrasound or magnetic resonance imaging. TRUE/FALSE
TRUE
What does attenuation mean?
The degree to which xrays are prevented from reaching the image receptor is referred.
What do the Shades of Gray are?
The different shades of gray on an image result from differences in in the absorption of the xray beam by the structures in its path.
Absorption based on composition (atomic number) means:
The higher the atomic number, the more absorption of the beam, the whiter the shadow on the image.
Why is it important to control the exposure to radiation?How can we manage it?
The human body absorbs the radiation which comes from the scatter, and it is important to control the exposure to radiation in order to be safe. This could happen by stay 6 feet away from the subject which gets the radiation during X-ray, and wear a lead vest.
Absorption based on tissue thickness means:
The thicker the part, the greater the absorption, the whiter the shadow.
smith fracture
The volar displacement of the distal fragment of the radius; sometimes called a reversed Colles fracture.
Scaphoid fracture
This patient has pain in her anatomical snuff box. -No radiographic evidence of a scaphoid fracture (left). -Fracture is apparent on the MRI shown (right). Scaphoid fractures may result in avascular necrosis of the proximal segment.
What shadow appearance will have at the X-ray a subject with High Atomic Number?
WHITE
What shadow color does the Radiopaque leave?
White shadow
what does fracture of bone mean?
a disruption of a bone's normal structure or continuity
insufficient means
abnormal
Immobilization
act of rendering immovable
where the pronator fat stripe is located?
at the anterior part of the wrist
where the scaphoid fat stripe is located?
at the lateral side of scaphoid bone
What shadow color does the Fat look like at the X-ray?
black
dislocation of joint
bony components of joint no longer intact
What shadow color does the Muscle tissue look like at the X-ray?
bright gray
What shadow color does the BaSO4 look at the X-ray?
bright white
pathologic fracture
caused by disease leading to weakness of the bone (bone tumors, bone cysts, osteomyelitis)
describe a fracture by its clinical distinction
closed/open
what does open fracture mean?
compound fracture
open fracture
compound fracture; broken bone with an open wound
transverse/horizontal/axial plane
cuts horizontally through the body and separates the body into upper (superior) and lower (inferior) sections
What shadow color does the Air look like at the X-ray?
dark black
What shadow color does the Organ tissue look like at the X-ray?
dark gray
abnormalities of position
describe relationship of distal fragment to proximal fragment
displaced fracture
distal fragment is offset from its normal location
sagittal plane
divides body into left and right
Midsagittal (median) plane
divides the body into equal right and left sides
alignment
do longitudinal axes line up?
distraction
ends of fragments have not contact
overriding or shortening
ends of fragments overlap
surgical interventions to fracture fixation
external/internal
non-displaced fracture
fracture fragments are anatomically aligned, in normal location
impacted fracture
fracture in which bone fragments are pushed into each other
longitudinal direction of fracture lines in relationship to shaft of the bone means
fracture is along the longitudinal plane of the shaft
transverse direction of fracture lines in relationship to shaft of the bone means
fracture is perpendicular to long axis of bone, usually results from direct impact
spiral direction of fracture lines in relationship to shaft of the bone means
fracture line spirals along the shaft, twisting fracture caused by torque injury (one end of extremity is fixed while the other end is in motion)
colles fracture
fracture of the distal radius at the wrist
oblique direction of fracture lines in relationship to shaft of the bone means
fracture passes at an angle oblique to the long axis of the bone
avulsion fracture
fragment is pulled from its parent bone by contraction of a tendon or ligament
What shadow color does the Blood tissue look like at the X-ray?
gray
the ----the amount of tissue absorption, the --- x-ray photons reach the film, and the ---- the image on the film.
greater/fewer/whiter
ring bone rule
if you see a fracture in a ring bone or ring bone equivalent then look for another one
why elbow fat pads are important?
important diagnostic tool to recognize fracture or dislocation
traumatic compression fractures occur
in normal bone via accidents
Decubitus position
in radiography, decubitus has a special meaning - patient is lying down & the x-ray beam is parallel to the floor (horizontal beam)
displacement
is distal fragment offset from its normal location (which direction)
angulation
is there an angle between fragments?
where the fat stripes of wrist located?
lateral to scaphoid bone and anterior portion of wrist
What shadow color does the Butter look like at the X-ray?
light black
low contrast means
low shades of gray
What does recumbent position mean?
lying back down and knees bend with hands in prone position
What R/L lateral recumbent position is?
lying down on the xx side R/L
Tissues/objects with a higher atomic number will absorb
more radiation than tissues with a lower atomic number.
what does comminuted extend fracture mean?
more than 2 fragments
Thicker tissues/objects will absorb
more x-rays than thinner tissue of similar composition.
sufficient means
normal
Avascular necrosis
of the proximal pole of the scaphoid. The proximal pole of the scaphoid (solid black arrow) is denser than the distal pole (solid white arrow). There is a fracture through the waist of the scaphoid (dotted white arrow). Because of the peculiar blood supply of the scaphoid (from distal to proximal), fractures through the waist may interrupt the proximal blood supply while the other bones of the wrist, having normal blood supply, become demineralized. This makes the proximal pole of the scaphoid appear denser relative to the other bones of the wrist.
ORIF stands for
open reduction internal fixation
subluxation of joints
partial dislocation
oblique plane
passes through the body at an angle
rotation fracture
rotation of the distal fracture fragment in relation to the proximal portion, it is most easily seen when looking at the orientation of the joints above and below a fracture
what are the fat stripes of wrist?
scaphoid and pronator
What shadow color does the Pb look at the X-ray?
sharp white
how the structure of bone cortex should appear when is normal?
should be more opaque when compared to normal cancellous bone and should be continuous without interruption, except in pediatric patient
posterior fat pad sign
should not be visible in a normal lateral elbow position, it should be within the olecranon fossa
describe a fracture by its extend
simple/comminuted
what adjectives do come before the superimposition term?
slight/near/complete
How does the erect positions can be distinguished?
surface of body closest to the IR used to give a more specific description
location of fracture
the anatomic location of the fracture usually described by giving the bone involved and the location on the bone
angulation fracture
the angle away from normal that the distal fragment makes with the proximal fragment
Absorption of x-rays is a function of
the atomic number and thickness of tissues/objects.
Central Ray (CR)
the placement of this will give us the most accurate image
Why Orthogonal projections are important?
to locate a subject more accurately
why fat stripes of wrist are important?
to underline a possible fracture
describe a fracture by its direction of fracture line
transverse/oblique/longitudinal/spiral
what are the directions of fracture lines in relationship to shaft of the bone?
transverse/oblique/spiral/longitudinal
calcaneal fractures
typically result from a fall and are often bilateral so radiographs of both should be examined. -A patient will have pain, swelling, and/or deformity of the hind foot. -A fracture can typically be seen on the lateral view.
frontal (coronal) plane
vertical plane dividing the body or structure into anterior and posterior portions
high contrast means
very black and white
what does erect "upright" position mean?
when the person in erect position and the receptor is next to it
What shadow color does the Bone look at the X-ray?
white
non operative techniques of fracture
•Closed reduction if required, followed by a period of immobilization with casting or splinting -Fragments guided into position by manipulation, traction or combination
plates and screws
•Commonly used in the management of articular fractures •Plate designs vary, depending on the anatomic region of the bone the plate is used for
advantages of external fixation
•Easy application •Good stability •Excellent pain relief •Adjustable -Alignment, Angulation, Rotation •Access to open wounds •Frequent dressing change •Monitoring of damaged tissue
types of internal fixation devices
•Kirschner wires (K-wires) •Plates and screws •Intramedullary rods and screws
healing complications
•Most often due to severe injury •Energy dissipation to bone and soft tissue results in damage to blood supply •Compartment syndrome •As pressure remains high, blood cannot get to damaged muscle •Neurovascular injury -Arteries and nerves around the injury site are damaged •Infection •Delayed union •Nonunion •Malunion •Post-traumatic arthritis •Growth abnormalities
Delay Fx. Healing
•Old age •Delayed immobilization •Too short a duration of immobilization •Poor blood supply •Steroids •Osteoporosis
operative techniques of fracture
•Surgical intervention •Where closed reduction fails, displaced intra-articular fractures, major avulsion fracture, nonunion, multiple fractures •Fracture fragments need to be fixed by: screws, wires, plates, external fixator devices
Lateral Projections
•The path of the x-ray beam is from one side of the patient/body part to the other. •The phrase "true lateral" indicates that care was exercised in positioning the path of the x-ray beam in the coronal plane.
viewing radiographic projections
•The traditional practice of viewing radiographs is simple and consistent. -For almost every body part the radiograph is viewed as if the patient is looking at you. This is true for any AP, PA, or oblique projection. •Exceptions -Hands, wrists, and feet are viewed as if you are looking at your own. -Forearms may be viewed either as if the patient is looking at you with elbows extended (anatomical position) or you are looking at your own forearms.
Kirschner wires (K-wires)
•When used as sole form of fixation, they are supplemented by casting or splinting. •Commonly used as adjunctive fixation for screws or plates
Accelerate Fx. Healing
•Youth •Early immobilization •Adequate duration of immobilization •Good blood supply •Physical activity after immobilization •Adequate mineralization
Salter-Harris Type V
•when there is a compression (crush) injury to the growth plate Worst prognosis
Salter Harris Type II
•when there is a fracture across most of the growth plate and up through the metaphysis Good prognosis
Salter-Harris Type III
•when there is a fracture across some of the growth plate and down through the epiphysis •Poorer prognosis as the proliferative and reserve zones are interrupted
Salter Harris Type I
•when there is a fracture across the growth plate with no bony involvement •Good prognosis
Salter-Harris Type IV
•when there is a fracture through metaphysis, growth plate, and epiphysis •Poorer prognosis as the proliferative and reserve zones are interrupted