Aqueduct Radiology Core practice questions and select Sonosim modules

Reasons for artificial cardiomegally on CXR

- AP projection - Epicardial fat - Pericardial effusion - Twisted patient - Low inspiration - Obesity increases the distance between you and the film - Pectus excavatum --> squishes the heart wide and thin, and lose right heart border

Nexus criteria: C-spine imaging in trauma unless all of the following (5 things) -

- Absence of posterior midline cervical spine tenderness - No evidence of intoxication - Normal level of alertness - Absence of focal neurological deficit - No clinically apparent painful injuries that might distract from pain of a cervical spine injury

BIRADS Categories and risk of breast cancer 0 1 2 3 4a 4b 4c 5 6

0 - need more information 1 - normal, 5:10K 2 - benign (cyst/postsurgical), 5:10K 3 - probably benign (short interval f/u), <2% 4a, 4b, 4c - suspicious for malignancy, 2-10%, 10-50%, 50-95% 5 - highly suspicious for malignancy, 75-99% 6 - known malignancy

What is the difference between a gray and a sievert?

1 Gray = 100 rads = how much radiation is absorbed by the body 1 Sievert = 100 rems = the biological effect of radiation

Radiation doses and time at sea-level equivalents: 1 year at sea level Radiograph of extremity DEXA scan CXR CT sinus Mammography CT Head CT Angiogram of intra/extraaxial vessels UGI study Barium enema CT A&P CT colonography

1 year at sea level = 3 mSv Radiograph of extremity = 0.001 msv ~ <1 day DEXA scan = 0.001 msv ~ <1 day CXR = 0.1 mSv ~10 days CT sinus = 0.6 mSv ~2 months Mammography = 0.7 mSv ~ 3 months CT Head = 2 mSv ~8 months CT Angiogram of intra/extraaxial vessels = 5 mSv ~20 months UGI study = 6 mSv ~ 2 years Barium enema = 8 mSv ~3years CT A&P = 10 mSv ~3years CT colonography = 10 mSv ~3years

Of screening mammograms, what percent get a callback? and of those called back, what percent have cancer?

10% get callbacks, and of those, 10% have cancer

What volume of fluid is needed before it can be seen on a PA CXR? Lateral CXR? CT?

150 cc of fluid on PA CXR 50 cc on lateral CXR 5-10 cc on CT

In evaluation of suspected aortic trauma on a supine chest radiograph (on trauma board), what is the imaging modality of choice? Select the one best answer.A. Contrast enhanced CT imaging B. MRI C. Catheter aortography D. Transesophageal echocardiography E. Erect PA chest radiograph (after clearance for spine injury)

> A has been selected by the expert. The correct answer is A (contrast enhanced CT imaging). CT imaging is the current modality of choice for evaluation of suspected acute aortic injury. Catheter andiography (previous "gold standard") is rarely done. Catheter angiography is still done in association with endovascular stent treatment of aortic injuries. MRI and TEE are not primary choices. They may be considered in patients with history of contrast allergy or renal insufficiency. An erect PA chest radiograph is a better test for evaluatio of possible mediastinal widening (since the mediastinum can appear widened on AP supine chest radiographs - especially in large patients). This is not commonly done in suspected trauma since CT imaging is the procedure of choice.

A 52 year old man with a 20 pack year history of smoking has an abdominal CT performed when he presents with diverticulitis. He has no prior imaging. A 12 mm spiculated nodule is seen in the peripheral right lower lobe. Which of the following would be an appropriate form of management? Select all that apply. A. CT guided needle biopsy B. PET-FDG scan C. Follow up CT in 6 months D. Bronchoscopy E. Contrast enhanced chest MRI

> A, B have been selected by the expert. The correct answers are A (CT guided needle biopsy) and B (PET-FDG scan). This is a highly supicious incidental finding in a high risk patient, so should not be followed. It is unlikely to be seen on bronchoscopy as it is small and peripheral. Contrast enhanced MRI is not indicated currently for this. Either a CT guided biopsy, or a PET scan with excision if positive are reasonable approaches.

n which of the following clinical scenarios should imaging of the cervical spine be performed according to the NEXUS Criteria? Select none, one, or more. A. 25 year old intoxicated man with neck pain after assault outside of a bar B. 86 year old man with dementia and left arm weakness after fall from bed C. 30 year old alert, sober helmeted female with no complaints and normal physical exam after bicycle accident D. 59 year old woman with pelvic fracture after motor vehicle accident

> A, B, D have been selected by the expert. A, B, and D are all exaples of appropriate scenarios for ordering imaging of the cervical spine according to the NEXUS Criteria. According to the NEXUS Criteria, cervial spine imaging is recommended for patients with trauma unless they meet ALL of the following criteria: Absence of posterior midline cervial-spine tenderness No evidence of intoxication Normal level of alertness Absence of focal neurological deficit No clinically apparent painful injuries that might distract from pain of a cervical spine injury

In which of the following clinical scenarios should a chest radiograph be performed according to the ACR Appropriateness Criteria? Select all that apply. A. 15 year old girl with a fever 39C and a cough for 4 days with inspiratory crackles in the right lung base B. 25 year old man with a fever 39.5C and a cough for a week with normal physical examination C. 86 year old man with dementia and fever 38.5C and a cough for a week but no localizing signs D. 30 year old asthmatic woman with cough productive of clear sputum, runny nose, and diffuse mild wheeze on examination E. 59 year old woman with fever 39.5C, cough productive of yellow sputum, and focal left upper lobe wheeze

> A, C, E have been selected by the expert. The correct answers are A, C, & E. A, C, and E are all examples of appropriate scenarios for ordering a chest radiograph in an immunocompetent patient. B and D are extremely unlikely to change management.

A non-contrast head CT in an elderly patient with altered mental status after a fall shows a high density crescent shaped collection along the right convexity causing mass effect on the underlying right cerebral hemisphere. In which space is the hematoma located? A. Epidural B. Subdural C. Intraventricular D. Subarachnoid E. Parencyma

> B has been selected by the expert. The correct answer is B. The subdural space is a potential space between the dura mater and the arachnoid mater. They are crescent shaped and can cross sutures but do not cross the falx. They are typically due to tearing of the bridging cerebral veins as they drain into the dural sinuses. Subdural hemorrhages can occur in elderly patients with minimal trauma due to cerebral atrophy.

In a patient with a suspected left sided pneumothorax which is not confirmed on the routine upright PA chest radiograph, which of the following imaging studies may be helpful? Select all that apply. A. Right lateral decubitus chest radiograph B. Left lateral decubitus chest radiograph C. Supine chest radiograph D. Expiratory chest radiograph E. CT scan F. MRI scan

A, D, E have been selected by the expert. The correct answers are A (right lateral decubitus chest radiograph), D (expiratory chest radiograph), and E (CT scan). A lateral decubitus radiograph with the ABNORMAL side up (i.e. the opposite decubitus as these are named for the 'down' side) would help show air against the chest wall. Putting the abnormal side down is not helpful. A supine chest radiograph is less sensitive than an upright one. Expiratory chest radiographs increase the sensitivity for detection of pneumothraces by increasting the density of the normal lung, and decreasing its volume relative to the pneumothorax. CT scans are the most sensitive modality for detecting a pneumothorax. MRI scans are unhelpful in this situation. Note, ultrasound can be used to detect pneumothoraces but it is still controversial how sensitive these are relative to the above modalities. There is likely a role in the trauma setting.

In which of the following conditions can air bronchograms be seen? Select one or more. A. Pneumonia B. Emphysema C. Pulmonary edema D. Pulmonary hemorrhage E. ARDS F. Pulmonary fibrosis

A. Pneumonia C. Pulmonary edema D. Pulmonary hemorrhage E. ARDS

Timing for acuity of bleed on non contrast head CT

Acute subdural <3 days = hyperdense (bright) on CT Subacute subdural (3days-3weeks) = isodense to gray matter on CT Chronic subdural >3weeks = hypodense

Ottawa Ankle Rules

An ankle series is indicated if the patient has pain near the malleoli and one or more of the following: Age 55 years or older Bone tenderness at the posterior edge of the tibia or tip of either malleolus Inability to bear weight immediately after injury and/or 4 steps in emergency room

What does ALARA stand for?

As low as reasonably achievable

What type of imaging modality is most commonly used as part of the simulation in contemporary Radiation Oncology practices? A. 2D X-rays B. CT scan C. MRI D. Ultrasound E. PET scan

B is the correct answer. CT scan is the most common imaging modality used for simulation. However, other types of studies like PET/CT and MRI are frequently coregistered with the CT scan to aid in target volume delineation.

How are gestations aged?

Before an embryo is seen, the mean gestational sac diameter is used for dating. The crown-rump length is then used until about 11-12 weeks when the biparietal diameter (BPD) becomes the most accurate. In later pregnancy, a combined figure using multiple biometric parameters is used calculated by computer software programs.

The purpose of the Tumor Board is best described by which of the following responses? A. Corporate members of healthcare enterprise who choose capital investments for cancer programs B. Fund raising and development efforts for the local affiliate of the American Cancer Society C. Physicians from multiple disciplines who gather to determine plans of care for cancer patients D. Subspecialty board-certifying authority for clinical competence of medical oncologists

C is the correct answer. Option C correctly describes the role and function of the Tumor Board in orchestrating with specialists from multiple medical disciplines the plans of care for individual patients with cancer diagnoses. Options A, B, and D are all patently false.

Which of the following is an indication using the ACR appropriateness criteria for obtaining a pre-op chest radiograph? Select all that apply. A. 37 year old woman with no cardiorespiratory symptoms currently but a history of asthma pre-op breast implants B. 73 year old asymptomatic man pre-op knee replacement C. 49 year old diabetic man with no cardiorespiratory symptoms currently pre-op ACL repair with crackles at the right lung base D. 78 year old woman with COPD, normal CXR 5 months ago and no acute sypmtoms, pre-op for a hip replacement E. 71 year old man with COPD, normal CXR 12 months ago and no acute symptoms, pre-op knee replacement

C, E have been selected by the expert. The correct answers are C and E. Although frequently requested, preoperative chest radiographs are rarely indicated. The two main indications are: Acute cardiopulmonary findings by a history or physical. Chronic cardiopulmonary disease in the elderly (>age 70), previous chest radiograph within 6 months not available.

Give the approximate effective radiation dose and comparable natural backgroud radiation (time) of the following: CT Abdomen and Pelvis Barium enema Intravenous Pyelogram (IVP) CT Head CT Chest PA CXR Mammography

CT Abdomen and Pelvis/10 mSv/3 years Barium enema/8 mSv/3 years Intravenous Pyelogram (IVP)/2mSv/1year CT Head/2 mSv/8 months CT Chest/7 mSv/2 years PA CXR/0.1 mSv/10 days Mammography/0.7 mSv/3 months

Ground-glass appearance

Can still see vascular markings. Seen in PJP pneumonia, atypical pneumonia

What type of imaging is best for the following indications: Change in chronic headaches Acute brain ischemia Cerebral hemorrhage Stroke Mass lesion Recurrent sinusitis

Change in chronic headaches - MRI Acute brain ischemia - DWI on MRI Cerebral hemorrhage - nonc CT Stroke - nonc CT Mass lesion - MRI w/o and w/ gadolinium Recurrent sinusitis - nonc CT max/face

Which one of the following is the most accurate imaging technique to diagnose an acute to subacute (up to one week) ischemic infarct in the brain? A. CT scan with contrast B. T1 MRI C. T2 MRI D. Diffusion weighted MRI E. MRI Flair

D. Diffusion weighted MRI

In which view of the cervical spine is a Hangman's fracture of C2 best seen? A. AP B. Oblique C. Open mouth D. Lateral

D. Lateral

Which of the following are most suggestive of benign calcification: A. Fine irregular branching calcifications B. Clustered microcalcifications C. Irregular mass with fine calcifications D. Lobulated mass with coarse calcifications

D. Lobulated mass with coarse calcifications

Timing of imaging after a stroke: DWI (earliest changes and when does it normalize?) CT (when normal? lose g/w diff? peak edema? hemorrhagic transformation?)

Diffusion weighted imaging will turn positive 20 minutes after stroke (d/t edema), and will normalize at 7-10 days CT will appear normal before 3 hours, 3-6 hours will loose gray/white differentiation, peak edema 48-72 hours, hemorrhagic transformation peaks 1-4 days.

Put the following radiographic procedures in order of radiation exposure to the patient (low to high). A. Chest radiograph B. Barium enema C. CT chest, abdomen & pelvis D. Extremity radiographs E. Head CT

E. D, A, E, B, C

When do you see the following on pelvic ultrasound: Gestational sac with yolk sac Fetal pole Heart beat limb buds organogenesis complete Yolk sac disappears

Gestational sac with yolk sac - 5 weeks Fetal pole - 6 weeks Heart beat - 5.5 to 6 weeks limb buds - 8 weeks organogenesis complete - 10 weeks Yolk sac disappears - 12 weeks

pretreat with prenisolone 50 mg 13h, 7h, and 1h prior, also give diphenydramine 50 mg 1 hr prior

Greenberger protocol for minor contrast allergy prophylaxis

A cancer patient presents with worsening liver function tests. Which of the following CANNOT be diagnosed by imaging? Select one or more. A. Hepatic metastases B. Biliary obstruction C. Portal vein thrombosis D. Drug-induced hepatitis

Imaging can detect new or increasing metastases, biliary obstruction, and portal vein thrombosis. It cannot detect chemotherapy-induced hepatitis.

Which of the following findings are compatible with SBO on a radiograph (select one or more): A. Collapsed colon and decreased colonic air B. Caliber of the small bowel is less than the colon C. Differential small bowel air fluid levels D. Absence of bowel sounds

In SBO, the small bowel is dilated to >3 cm wide. The small bowel is dilated out of proportion to the large bowel. The large bowel is decompressed with a complete SBO, while an early or partial SBO may have some gas in the large bowel. There may be air fluid levels at different levels in the same bowel loop on the upright radiograph ("differential air-fluid levels" due to continued normal/increased peristalsis). There are high-pitched bowel sounds on clinical exam. In adynamic ileus, there is lack of peristasis, and air fluid levels may be seen at the same level within a single loop. Bowel sounds are absent. Small bowel caliber is usually less than the large bowel.

You are in the Emergency Department caring for a 3 month old infant with poor weight gain and fussiness who was brought to the ED by his mother and her boyfriend. The child underwent a skeletal survey showing metaphyseal corner fractures. Which of the following are the most appropriate initial step in this patient's management? A. Admit child and make call to child protective services B. Refer for outpatient evaluation of infantile feeding disorder C. Confront the adults with the child and call police D. Choose soy-based formula for improved nutrition

Option A is the best answer because physicians are required in all U.S. jurisdictions to report findings that are suspicious for child abuse or child neglect. Metaphyseal corner fractures are among the most specific injuries for non-accidental trauma, and child abuse must be strongly suspected when these fractures are found.

A 4-week-old child in your clinic has a distinct "clunk" when you abduct the child's flexed knees with your thumbs as you apply anterior pressure on the greater trochanters (Ortolani maneuver). This finding indicates imaging is needed. Which of the following imaging studies is most appropriate in this setting? A. hip arthrogram B. hip ultrasound C. pelvis radiographs D. pelvis CT E. pelvis MR

Option B, hip ultrasound, is the best response, as ultrasound is quick, noninvasive, and effective in characterizing the normal or abnormal morphology of the hip joint and the cartilaginous femoral head in children 4-6 weeks of age without exposing the child to radiation or needle puncture of the joint.

An ex-27-week gestational age premature infant has increasing head size documented at 22 days postnatal life. His head circumference has jumped from 30th percentile to 90th percentile since the last measurement. Which of the following is the best choice to image the cranium? A. MRI B. CT without contrast C. Skull radiography D. Cranial ultrasound

Option D is the best response in this setting. Ultrasound is effective, portable, quick, and relatively cheap. The American College of Radiology Practice Guidelines for Neurosonography of preterm and term neonates and infants lists indications for cranial ultrasound as: to screen for hemorrhage or parenchymal abnormalities in preterm and term infants, to evaluate for hemorrhage, to evaluate for hydrocephalus, to evaluate for the presence of vascular malformations, to evaluate for possible or suspected hypoxic or ischemic encephalopathy, to evaluate for the presence of congenital malformations, to evaluate patients with signs and/or symptoms of central nervous system disorder, e.g., seizures, facial malformations, for screening or surveillance of previously documented abnormalities including prenatal abnormalities, and for screening prior to surgical procedures (Rev. 2009 http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/US_Neurosonography.pdf accessed Jan 16, 2014).

Which of the following is an appropriate indication(s) for image-guided paracentesis in a patient requiring a diagnostic paracentesis? Select one or more. A. Patient with bowel ileus with dilated bowel loops B. Patient with large body habitus and suspected infected ascites C. Patient with suspected hepatosplenomegaly D. Patient with low volume ascites E. Patient with bleeding diathesis

Patient with underlying ileus and ascites would definitely benefit from image guidance in order to avoid dilated bowel loops (A). Large body habitus will make external body landmarks unreliable and thus call for image guidance(B). Hepatomegaly and/or bleeding diathesis would make non-guided biopsy hazardous (C,E). Small amounts of ascites are ideally sampled with image guidance in order to insurance successful needle placement (D).

The RECIST criteria are used to characterize which of the following tumor characteristics? A. Local Invasion B. Metastic capability C. Response to chemotherapy D. Vascularity E. Cellular density

RECIST, or Response Evaluation Criteria in Solid Tumors, is the standard system used by oncologists to evaluate a patient's response to chemotherapy. It places all patients into one of 4 categories (Progressive disease [PD}, stable disease [SD], partial response [PR], and complete response [CR]). While it primarily utilizes tumor size, recent modifications are being introduced that take into account other factors that can be seen with imaging, such as tumor density, FDG PET avidity, cavitation, etc.

A PA chest radiograph in a patient with suspected pneumonia shows a confluent opacity in the right lung obscuring the right heart border. In which lobe is the pneumonia located?

Right middle lobe

Define the following MSK signs: Sail sign Posterior fat pad sign Honda sign

Sail sign - anterior fat pad of elbow pushed out by fluid of elbow effusion Posterior fat pad sign - normally don't see any type of posterior fat pad, if there is a BIG elbow effusion, then will see posterior fat pad Honda sign - on bone scan, will see uptake in H shape in sacrum, indicating sacral insufficiency

Regarding colorectal cancer screening in average risk individuals, which of the following radiologic examinations is rated the MOST appropriate by the ACR Appropriateness Criteria for colorectal? A. CT Colonography B. Double contrast barium enema C. MR colonography D. Single contrast barium enema

The correct answer is A. According to the ACR Appropriateness Criteria, CT colonography (CTC) is the preferred examination for colorectal cancer screening, and for completion of screening after incomplete optical colonoscopy. Sesitivity and specificity for detection of polyps =/> 6mm is greater for CTC than DCBE. Literature has shown a markedly inferior performance profile for the single-contrast barium enema compared to double contrast barium enema, and the role of MR colonography is under investigation.

A 54-year-old female with no significant past medical or family history has her annual physical exam and receives a referral for a mammogram. How often should she be getting a screening mammogram? A. Annually B. Semi-annually C. Bi-annually D. Only when she has a breast problem

The correct answer is A. Although this is an area of great controversy, the ACR/ACS/NCCN/ACOG organizations recommend annual mammogram screening starting at age 40. The American Medical Association makes less a specific recommendation, stating that women should be eligible for screening mammography at the age of 40 and that screening is a decision made between the patient and her physician

A 68 year old man is brought to the Emergency Department for evaluation of onset of aphasia and right side weakness upon awakening. Which of the following initial examinations is most appropriate in this circumstance? A. Contrast enhanced CT brain B. Non-contrast enhanced CT brain C. CT-angiogram D. Catheter angiogram

The correct answer is B. According to the American College of Radiology Appropriateness Criteria Nov 2013 update, Neurologic Imaging Criteria - Cerebrovascular disease, Non-contrast enhanced CT (B) is preferred as the initial exam, because it is quick and effective to detect if hemorrhage is present, and will thus guide immediate patient management. This patient's sudden change strongly suggests a vascular event such as an acute infarction. Option A, Contrast enhanced CT brain is not the best choice for initial examination because the use of contrast adds unneeded expense, risk of reaction, and potentially may obscure hemorrhage. Option C, CT-angiogram is not the best choice for initial examination, as its role is for problem solving after an initial non-contrast CT has demonstrated abnormal findings. Option D, Catheter angiogram is not the best choice for initial examination because its role is for problem solving after an initial non-contrast CT has demonstrated abnormal findings, and has raised questions for which catheter angiography would be suited, or revealed abnormalities that require catheter based therapy.

Which of the following would be the MOST appropriate clinical indication for performing brain MR Spectroscopy? A. Distinguish acute from chronic hemorrhage B. Distinguish Toxoplasmosis from Lymphoma C. Identify primary tumor in brain metastases D. Diagnose a brain abscess

The correct answer is B. MR Spectroscopy (MRS) is used clinically to distinguish Toxoplasmosis from Lymphoma. MRS is not indicated or helpful in characterization of hemorrhage, which is well accomplished with routine MR. MRS does not identify the primary source of lesions in cases of metastases, but can suggest a metastatic focus rather than a primary glial neoplasm, as primary brain tumors have different metabolites than metastases (which lack NAA). Diffusion weighted MR is more robust for identification of brain abscess than MRS, and the routine sequence and clinical context typically allows the confident diagnosis of abscess without resorting to MRS.

Which of the following diagnoses might make you consider screening for intracranial aneurysms? A. Mitral valve prolapse B. Adult polycystic kidney disease C. Severe COPD D. Ulcerative Colitis.

The correct answer is B. The incidence of congenital berry aneurysms is 10% in adult polycystic kidney disease. Both MR angiogram and CT angiogram may be used to screen these patient since they are noninvasive and both have excellent sensitivity and specificity for aneurysms >= 3 mm. The other conditions listed above do not have a known association with intracranial berry aneurysms.

A 41-year-old female presents to her gynecologist complaining of a lump in her right breast. Her physician palpates a 2 cm lobular, non-mobile mass in the right upper outer breast. What is the most appropriate next step in the work-up of this mass? A. Surgical excision B. Diagnostic mammogram C. Follow-up physical exam after 2 menstrual cycles D. MRI E. Breast ultrasound

The correct answer is B. In women > 40 years with a palpable mass, mammography is the most appropriate imaging exam for the initial evaluation according to the American College of Radiology (ACR) Appropriateness Criteria. This may be followed by ultrasound to determine whether the lesion is cystic or solid. It is important to make sure that the imaging findings directly correlate with the palpable abnormality.

A 28-year-old male presents with acute onset of flank pain and gross hematuria. What is the most appropriate initial imaging examination? Select one. A. Ultrasound B. Intravenous urography C. CT without intravenous contrast D. CT with intravenous contrast E. Radiograph

The correct answer is C. According to the ACR Appropriateness Criteria, CT without use of contrast material is the best first study in the non-pregnant adult patient presenting with acute onset flank pain and suspicion of stone disease. Non-contrast CT has been shown to be the examination with the highest sensitivity, specificity and cost-effectiveness compared to the other answer choices. CT performed with intravenous contrast material can obscure small stones and poses the risk of contrast-induced nephropathy and contrast reactions in some patients. Overlying bowel contents contribute to the relatively low sensitivity and sensitivity of radiography in this setting. Intravenous urography can be time consuming in the setting of acute obstruction and lacks the ability to identify alternative diagnoses. US is suboptimal due to limited evaluation of the ureter, inability to accurately measure stone size, and inability to differentiate renal collection system dilatation due to obstruction from cases of dilatation without obstruction.

Which of the following is the MOST appropriate ranking of imaging in a 32 year old pregnant patient with RLQ pain? (most appropriate to least appropriate) A. US, CT, MRI B. MRI, CT, US C. US, MRI, CT D. CT, US, MRI E. CT, MRI, US

The correct answer is C. Ultrasound is the safest imaging modality and in fact is used for much of obstetric imaging, so it is the first line modality for maternal disease (such as appendicitis or ovarian torsion) that may occur during pregnancy. MRI has no known deleterious fetal effects and, although more expensive and time consuming, it would be the next step if the ultrasound is non-revealing. Finally, when indicated, CT scan suspected abdominal disease in pregnancy can be performed, especially when beyond the first trimester, but this would be the last choice.

A 55-year-old female is recently diagnosed with cervical cancer. What is the most accurate imaging modality for staging cervical cancer? A. Plain films B. PET scan C. MRI D. CT E. Ultrasound

The correct answer is C. MRI is considerably more accurate than CT (90% vs. 60%) as well as the other modalities, and MRI is now considered the standard of care for cervical cancer staging.

When is imaging recommended in cases of clinically suspected pyelonephritis? Select one. A. Imaging is indicated in the majority of cases. B. It is recommended in adults after their second episode. C. It is recommended in diabetics and immunocompromised patients with no response to medical therapy within 24 hours. D. It is recommended in otherwise healthy patients at the completion of medical therapy. E. It is recommended in all patients over 70 years old.

The correct answer is C; It is recommended in diabetics and immunocompromised patients with no response to medical therapy within 24 hours. In the majority of patients, acute uncomplicated pyelonephritis is readily diagnosed clinically and typically responds to antibiotics. Therefore, most cases of clinically suspected pyelonephritis do not require imaging. According to the ACR Appropriateness Criteria, pre and post-contrast CT is the imaging study of choice to evaluate for complications of acute pyelonephritis (such as renal or perinephric abscess or emphysematous pyelonephritis). In an otherwise healthy patient, CT should be pursued if there is no response to treatment in 72 hours. In diabetics or immunocompromised patients, CT should be obtained if there is not prompt response to medical therapy within 24 hours of diagnosis. For otherwise healthy patients who respond to and complete medical therapy, no imaging follow-up is recommended. Ultrasound typically underestimates the degree of pyelonephritis and perinephric extension. Hydronephrosis is an uncommon manifestation of acute pyelonephritis.

Which of the following MRI sequences is the MOST sensitive for the detection of early cerebral infarction? A. T1 B. T2 C. FLAIR D. Diffusion weighted images (DWI)

The correct answer is D. DWI sequences can show hyperacute infarction as soon as 20 mins after cerebral infarction. T1 and T2 are nowhere near as sensitive. FLAIR (FLuid-Attenuated Inversion-Recovery) are very sensitive to edema but still not as sensitive for very acute infarction.

What is the most appropriate initial imaging method for evaluating a patient with clinical change in chronic headache? A. Radiographs of skull B. CT scan with contrast C. CT scan without contrast D. MRI Brain

The correct answer is D. For a patient with a change in their chronic headache, the best modality is MRI; contrast may be used as per discretion of the radiologist. CT scan without contrast is best for acute onset severe headache given its excellent sensitivity for detection of acute intracranial hemorrhage, which is the diagnosis of exclusion in the acute setting. CT scan with contrast would not be indicated as contrast can potentially obscure acute intracranial hemorrhage (both contrast and acute hemorrhage are hyperdense to brain). CT may also be done if MRI is contraindicated. Radiographs of the skull are usually not used in work up of headache.

What is the most SPECIFIC sonographic criterion for the diagnosis of acute cholecystitis? CORRECT A. Gallstones B. Gallbladder wall thickening C. Pericholecystic fluid D. Sonographic Murphy's sign E. Common bile duct dilatation

The correct answer is D. While gallstones (A) are frequently the cause of cholecystitis, they may be present without causing cystic duct obstruction. Gallbladder wall thickening (B) may be caused by many other diseases that lead to edema of the gallbladder, including hepatitis, pancreatitis, hypoalbumenemia of any cause, and congestive heart failure. Common bile duct dilatation (E) may be either obstructive (distal duct stone, stricture, or mass) or non-obstructive (due to aging or prior bile duct obstruction). Sonographic Murphy's sign (D), when properly performed, is the most specific sign of acute cholecystitis.

Regarding administration of iodinated intravenous contrast material, which one of the following is true? A. Metformin therapy is an absolute contraindication. B. The combination of diphenhydramine, aspirin and cimetidine is an accepted prophylaxis for a patient who developed hives after receiving iodinated intravenous contrast material in the past. C. Contrast induced nephropathy (CIN) manifests as persistently elevated serum creatinine beginning 2-4 hours after exposure to iodinated contrast material. D. Treatment of contrast-induced nephropathy (CIN) is the same as that for acute renal failure due to other causes. E. Dialysis dependent patients are not eligible to receive iodinated contrast material.

The correct answer is D; Treatment of contrast-induced nephropathy (CIN) is the same as that for acute renal failure due to other causes. Metformin therapy is a relative contraindication to receiving iodinated intravenous contrast material; this medication is typically discontinued for two days after contrast material administration and then restarted if serum creatinine remains normal to prevent development of lactic acidosis. Accepted prophylaxis for patients with documented, non-anaphylactoid reactions to iodinated contrast material consists of corticosteroids and diphenhydramine; aspirin plays no role in this situation. CIN manifests as a transient rise in the serum creatinine level three to six days after exposure to iodinated intravenous contrast material. Treatment of CIN is the same as that for acute renal failure due to other causes; more severe cases may require temporary hemodialysis. Dialysis dependence is not a contraindication to receiving iodinated contrast material.

A 39 year old man suffered femur and tibial fractures in a motor vehicle accident one day ago. He had orthopedic surgical fixation. While being transported from the post anesthesia recovery area to his hospital room, he had a drop of his O2 saturation from 98% to 75%. Which of the following is the most accurate study to evaluate for pulmonary emboli? A. D-dimer assay B. V/Q scan C. Lower extremity doppler US D. Chest radiograph E. CT angiogram

The correct answer is E (CT angiogram). Of the responses offered, ONLY CTA for PE directly demonstrates emboli in the lumens of the pulmonary arteries. All the other studies are less direct, and depend on indirect evidence, as outlined in the module.

Focal bowel wall thickening and free intraperitoneal fluid are the only findings on a CT scan of a 30 year old male following a motor vehicle collision. Which of the following is true? Select one or more. A. A small amount of free intraperitoneal fluid may be a normal finding. B. Bowel injury is unlikely since there is no free intraperitoneal gas. C. Bowel injury must be considered. D. The bowel wall thickening is likely due to over-hydration.

The correct answers are A (A small amount of free intraperitoneal fluid may be a normal finding) and C (Bowel injury must be considered). Even in the setting of trauma, due to the over-hydration given to protect the kidneys, free intraperitoneal fluid (choice A) may be an expected finding, in either sex or at any age, but should be considered with other findings, especially if the amount or the density (HU) is increased. While pneumoperitoneum, or free intraperitoneal gas, is fairly specific for a bowel perforation in the setting of trauma, its absence does not exclude a bowel injury (choice B). In the setting of trauma, bowel wall thickening is concerning for a bowel injury and should not be ascribed to nontraumatic etiologies (choice D). In the setting of blunt trauma, the combination of bowel wall thickening and free intraperitoneal fluid is concerning for, but not pathognomonic for, a bowel injury (choice C).

Given fractures of the left acetabulum and left sacral ala, without widening of the pubic symphysis, which of the following studies would be helpful to evaluate for potential associated bladder injury? (More than one answer may be correct.) INCORRECT A. CT cystogram B. Routine CT with delayed images through the bladder C. Retrograde cystogram D. Retrograde urethrogram

The correct answers are A (CT cystogram), and C (Retrograde cystogram). The radiograph demonstrates fractures of the left acetabulum and left sacral ala. The pubic symphysis is not widened. Bladder injury is possible in the setting of severe pelvic fractures. A routine CT with delayed images (choice B) may be insufficient to diagnose a bladder injury as the bladder may not be optimally distended. Subtle bladder injuries can be missed when the bladder is not completely distended. Therefore, either a CT cystogram (choice A) or a retrograde cystogram (choice C) are needed since both studies directly inject contrast into the bladder to attain optimal distention. A retrograde urethrogram (choice D) is indicated in the setting of a widened pubic symphysis or if there is blood at the penile meatus to evaluate for urethral injury.

Why is evaluation of the density of a patient's breasts on a mammogram important? (Select one or more answers.) A. Breast cancer risk increases with the density of the breast. B. Mammograms are more sensitive for the detection of cancer in dense breasts. C. Dense breasts may be candidates for adjunctive screening methods, such as MRI and ultrasound. D. The denser the breasts the more often screening should be performed. E. Mammograms are more painful in dense breasts.

The correct answers are A and C. Breast cancer risk increases with the amount of fibroglandular tissue (=density) and the sensitivity of mammography decreases. Patients with dense or heterogeneously dense breasts may be offered adjunctive methods of screening in some centers, particularly if they have additional risk factors. In some states, there is a legal requirement to inform patients of their breast density and its significance.

Which of the following is true regarding a dual-energy x-ray absorptiometry (DEXA) scan? (Select none, one, or more.) A. It measures bone mineral density (BMD). B. It requires more radiation than quantitative computed tomography (QCT). C. The T score is a patient's bone density compared with what is normally expected in a healthy young adult of the same sex. D. It is particularly useful in patients with extensive degenerative joint disease. E. Only one site (spine or hip) needs to be measured.

The correct answers are A and C. DEXA scans are used to screen patients for osteoporosis. They require less radiation than quantitative computed tomography; however, they are not as effective in patients with extensive degenerative disease, where values can be falsely elevated secondary to bone sclerosis. The DEXA radiation dose is very small. A T score is the number of standard deviations from the mean of an individual's BMD compared to the gender-matched individual of ideal peak bone density, not age-matched. The Z score is the number of standard deviations from the mean of an individual's BMD of a gender and age-matched healthy adult. Some also correct for race. (This website from the University of Washington has a nice summary of these scores.) WHO definitions are: Normal bone: T-score better than -1 Osteopenia: T-score between -1 and 2.5 Osteoporosis: T-score less than -2.5 Established (severe) osteoporosis includes the presence of a non-traumatic fracture. Measuring both hip and spine better predicts the risk for both vertebral and hip fractures.

In patients with biliary duct obstruction, which of the factor(s) would favor choice of MRCP (MR cholangiocholangiogram) over ERCP (endoscopic retrograde cholangiopancreaticogram) in a patient with work-up of biliary duct obstruction? (Select one or more) A. Patient with severe COPD B. Patient requiring CBD stenting C. Patient with cardiac pacemaker D. Patient with suspected acute pancreatitis

The correct answers are A and D. ERCP requires conscious sedation and thus may be unsafe in a patient with pre-existing respiratory compromise. MRCP can be used safely in a patient with COPD (A). However if a bile duct stent is required, this would necessitate ERCP (B). Cardiac pacemakers can be depolarized during MRI leading to malfunction, and thus these patients cannot safely undergo MRI (C). ERCP may cause or exacerbate pancreatitis and thus would be an unsafe choice (D).

Which of the following are indications for annual screening breast MRI? (You may select more than one.) A. A 45-year-old with a history of Hodgkins lymphoma treated with mantle radiation 20 years ago B. A 60-year-old with breast cancer treated with neoadjuvant chemotherapy C. A 15-year-old who is positive for the BRCA1 gene D. A 35-year-old with a 28% lifetime risk of developing breast cancer on the basis of family history E. A 67-year-old post-lumpectomy for breast cancer with positive margins on pathology

The correct answers are A and D. The patients in answers A and D are women at high risk of developing breast cancer and thus may benefit from the increased sensitivity of MRI breast cancer screening over conventional mammogram. Evaluation of a known breast cancer with MRI after neoadjuvant chemotherapy would be a "diagnostic" MRI evaluating for extent of residual disease prior to definitive surgery, not a screening MRI. Screening MRI for a BRCA mutation carrier could start as young as 25 but not at the age of 15. Evaluation of a post-lumpectomy patient with positive margins would be a diagnostic MRI evaluating for extent of disease, not a screening MRI.

Which of the following choices is a contraindication for methotrexate treatment for an ectopic pregnancy? (Select all that apply.) A. Tubal mass is 4 cm or larger B. Embryonic heart motion present C. Prior ectopic D. Mild pelvic pain E. Immunosuppressed state

The correct answers are A, B and E. A patient is a candidate for methotrexate treatment if: the tubal mass of the ectopic pregnancy is < 4 cm embryonic heart motion is absent there is no hemoperitoneum, and the patient is hemodynamically stable and without severe pain. If there are contraindications to methotrexate-such as immunodeficiency, hematologic disease, active pulmonary disease, peptic ulcer disease, renal or liver disease-methotrexate is not administered.

Which of the following statements about intraperitoneal bladder rupture is true? Select one or more. A. It can be excluded by delayed IV contrast enhanced CT pelvis with a clamped Foley B. Extravasated bladder contrast surrounds loops of bowel on a CT or KUB C. It requires immediate surgery D. Is best diagnosed with a retrograde urethrogram

The correct answers are B (extravasated bladder contrast surrounds loops of bowel on a CT or KUB), and C (it requires immediate surgery). Bladder rupture cannot be confidently assessed without a dedicated CT cystogram or fluoroscopic retrograde cystogram. Bladder distention with a clamped urethral catheter alone does not result in sufficient bladder distention (choice A). The hallmark finding of an intraperitoneal bladder rupture is extravasation of bladder contrast into the peritoneum, as can be confirmed by contrast surrounding loops of bowel (choice B). While extraperitoneal bladder ruptures can be managed conservatively, with bladder decompression alone (choice D), an intraperitoneal bladder rupture must be surgically repaired (choice C).

Spine sign

The spine sign is seen when there is a posterior lower lobe opacity on a lateral chest radiograph. As the eye scans down the spine, it should get more lucent (or at least not denser), aside from some linear vascular markings until the first hemidiaphragm is reached. If it becomes more opaque, such as in the example above, there is a soft tissue or fluid density abnormality there. It can be caused typically by pneumonia, but can also be seen in atelectasis and masses. It will obscure the posterior portion of a hemidiaphragm depending on laterality.

Typical radiographic findings in posterior dislocations

Typical radiographic findings in posterior dislocations include no change in alignment on internal and external rotation views: shoulder is "fixed" in internal rotation.

Language to describe: US XR CT MRI

US = echoic --> hyper (white, bone/fat) or hypoechoic or anechoic (black, fluid) XR = opaque/lucency CT = hypo/hyper dense or attenuating, if IV contrast, then enhancing MRI = hypo/hyper intense (T1 fat is bright, T2 fluid bright)

Signs of atelectasis of left upper lobe?

Volume loss in the left hemithorax (smaller overall) Tracheal deviation to the left Left hemidiaphragm elevation (but can still be seen) Hazy opacity over the mid and upper left hemithorax ('ground glass' - still can see the vascular markings of the left lower lobe through it) Loss of left heart border (which the left upper lobe abuts)

lipohemarthrosis

a mixture of fat and blood within the joint capsule following trauma. This is a very important finding as it indicates an intraarticular fracture. Fat and blood are released from the marrow space and enter the joint through the osteochondral defect of the fracture at the articular surface. Fat is less dense than blood and hence will float to the surface. Hence the presence of a fat-fluid level is nearly diagnostic of a fracture, even when the fracture is radiographically occult.

Hounsfeld units of: Air water fat bone metal

air = -1000 fat = -120 to -90 water = 0 bone = +200 to +700 metal = + 14k to +30k

Live intrauterine pregnancy?

any embryo in the uterus measuring more than 5 mm must have identifiable cardiac activity

Meniscus sign

curved line seen from a pleural effusion as it abuts the posterior or lateral pleura.

Abnormal intrauterine pregnancy (embryonic demise)

gestational sac diameter at least 10 mm but no yolk sac OR fetal pole with crown-rump length at least 5 mm and no cardiac activity

In which of the following clinical scenarios should an MRI of the foot be performed for evaluation of osteomyelitis according to the ACR Appropriateness Criteria? (Select none, one, or more.) A. An 83-year-old female with diabetes mellitus with soft tissue swelling and without neuropathic arthropathy or ulcer B. A 63-year-old male with diabetes mellitus with soft-tissue swelling and ulcer C. A 69-year-old female with diabetes mellitus with soft-tissue swelling, neuropathic arthropathy, and ulcer D. A 76-year-old male with diabetes mellitus with soft-tissue swelling and neuropathic arthropathy and without ulcer

he correct answer: All (A, B, C, and D) All choices are correct. Radiographs and MRI are complementary in all scenarios, and both are indicated.

When an Extended Focused Assessment with Sonography for Trauma (eFAST) scan is performed, which of the following are assessed? Select one or more. A. Is there pericardial fluid? B. Is there perihepatic fluid? C. Is there a pneumothorax? D. Is there ovarian torsion?

he correct answers are A (Is there pericardial fluid?), B (Is there perihepatic fluid?), and C (Is there a pneumpthorax?). FAST scans are limited ultrasound examinations intended to look for free intraperitoneal (choice B) and pericardial fluid (choice A), which, in the setting of trauma, is worrisome for hemoperitoneum and hemopericardium respectively. FAST can detect a pneumothorax (choice C), but not all centers utilize FAST for detection of a pneumothorax; if scanning of the thoraces is added, the scan is called an eFAST. While ultrasound is an excellent modality to evaluate the ovaries, it is not a component of the FAST scan.

Radiation in pregnancy: threshold of risk of abortion timeline for highest risk

if over 50 mSv, then risk abortion riskiest 8-15 wks (organogenesis), although neurotoxicity 8-25 wks

Continuous hemidiaphragm sign

is a sign of a pneumomediastinum on a chest radiograph when there appears to be a lucent line connecting both hemidiaphragms due to air between the pericardial sac and the diaphragm

Two pelvic ultrasound findings indicative of extrauterine gestation:

live extrauterine embryo with cardiac activity extrauterine gestation sac containing yolk sac or fetal pole

Endometrial thickness in: - post-menopausal woman not on HRT - post menopausal woman on tamoxifen

not on HRT = 4-5 mm on tamoxifen = up to 8 mm

Deep Sulcus sign

pneumothorax on a supine chest radiograph, where on costophrenic sulcus appears much deeper and lucent than the other due to air collecting there.

If screening mammography in 1000 women, then how many recalls? how many biopsies? how many have cancer?

screen 1000 women, call back 100 women for ultrasound, biopsy 20 women, cancer in 4-5 women

Rigler's sign

sign of a pneumoperitoneum on a supine or decubitus abdominal radiograph when air is seen on both sides of the bowel wall. Here is an example of Rigler's sign on a decubitus study.

Calcifications worrisome features on mammography

small size or pleomorphic more particles fine linear or branching segmental, ductal branching, or linear distribution

Describe the cancer risk with radation

stochastic risk: linear no threshold model (the more you receive over the years, the more your cancer risk increases, but there is no certain threshold over which you will definitely get cancer)

When to use MRI in breast cancer?

with contrast gadolinium, for breast cancer that is already diagnosed or if have a >25% lifetime risk of breast cancer

Unilateral hemithorax opacification differential, and whether it causes decreased or increased volume

○ Pneumonectomy--> decreased volume on abnormal size ○ Complete atelectasis -->decreased ○ Pleural effusion --> increased ○ Pneumonia -- same volume ○ Mass --> increased Aplasia of lung in neonate --> decreased