Question 1

B. Correct! This is acute calculous cholecystitis. This has the classic appearance of an obstructing stone in the gallbladder neck, with wall thickening, and wall hyperemia on Doppler. (As noted in the history, there was a reported positive sonographic Murphy sign as well.)

Other choices and discussion

A. Gallstones are present, excluding acalculous cholecystitis. Acute inflammation of the gallbladder in the absence of stones is termed acalculous cholecystitis.

C. The classic “comet-tail” artifact of adenomyomatosis is not present in this case.

D. No mass lesion or mass-like wall thickening is present to suggest neoplasm.

E. No air or “dirty shadowing” is present to suggest emphysematous cholecystitis.

Question 2

B. Correct! The sonographic Murphy sign is the most sensitive sign for this diagnosis. A sonographic Murphy sign refers to pain from transducer palpation over the gallbladder with inspiration. A sonographic Murphy sign is associated with 90% of cases of acute cholecystitis. Typically, the gallbladder is visualized, and the patient is instructed to take a deep breath while the sonographer increases transducer pressure.

Other choices and discussion

A. Air within the gallbladder lumen is a very uncommon finding. In the setting of emphysematous cholecystitis, air is present within the wall of the gallbladder.

C. The presence of gallstones (cholelithiasis) is common, but not the most sensitive finding. In addition, gallstones are often seen in the absence of acute inflammation. Gallstones may be clinically asymptomatic or result in intermittent biliary colic.

D. Vascular flow is typically increased in the setting of acute cholecystitis, although this is not the most sensitive finding. Pronounced flow in the cystic artery is occasionally seen with Doppler.

E. Gallbladder distention commonly occurs with fasting in normal patients.

Question 3

E. Correct! Emphysematous cholecystitis is a surgical emergency. Emphysematous cholecystitis refers to acute inflammation of the gallbladder due to gas-forming bacteria. It carries an increased risk of gallbladder perforation, peritonitis, sepsis, and death. Therefore, emergent cholecystectomy is indicated.

Other choices and discussion

A. Emphysematous cholecystitis is seven times more common in males than in females.

B. Up to half of the patients with emphysematous cholecystitis do not have gallstones.

C. Up to half of the patients with emphysematous cholecystitis do not have gallstones.

D. The prevalence of emphysematous cholecystitis is increased in patients with metabolic disorders. Up to one-half of the patients with emphysematous cholecystitis have diabetes mellitus.

Question 1

C. Correct! This is adenomyomatosis. Pictured is the classic “comet-tail” artifact, which occurs secondary to ultrasound wave reflections off cholesterol crystals within sinuses of the gallbladder wall.

Other choices and discussion

A. No sonographic signs are seen to suggest cholecystitis, such as gallbladder wall thickening or pericholecystic fluid. In addition, the patient is reportedly asymptomatic.

B. No gallstones are seen.

D. No mass lesion or mass-like wall thickening is seen.

E. Air would result in more pronounced shadowing in the gallbladder wall than is seen in the test case, and the patient would likely be symptomatic with emphysematous cholecystitis.

Question 2

A. Correct! Adenomyomatosis has no malignant potential. While adenomyomatosis has been identified in some resected gallbladder carcinoma specimens, no direct relationship between the two conditions has been definitively established.

Discussion

The other options are incorrect. Surgical treatment of isolated adenomyomatosis is not indicated in the absence of symptoms.

Question 3

C. Correct! The hallmark of adenomyomatosis is prominent epithelial sinuses (Rokitansky-Aschoff sinuses), which herniate into the gallbladder wall. Cholesterol crystals may deposit in these sinuses, giving a characteristic comet-tail artifact.

Other choices and discussion

A. This is not due to adherent gallstones.

B. This is not due to intramural gas. Intramural gas is seen in the setting of emphysematous cholecystitis and is a surgical emergency, due to the risk of gallbladder perforation. It does not progress to adenomyomatosis.

D. Patients with adenomyomatosis may also have cholecystitis. However, this condition does not lead to the formation of adenomyomatosis.

E. Inflammatory polyps are a less common form of gallbladder polyposis. They are usually associated with longstanding cholelithiasis.

Question 1

A. Correct! This is a hemangioma. Hepatic hemangiomas typically present as well-defined hyperechoic masses with no flow on Doppler. They are common incidental findings on imaging of the liver, with some studies reporting them in up to 20% of the population.

Other choices and discussion

B. Fibrolamellar hepatocellular carcinoma is a hepatic mass that typically presents in 20- to 40-year-olds. Although it is less aggressive than hepatocellular carcinoma, it does not produce symptoms until later in the disease, so it often presents as a large mass, unlike the test case.

C. Abscess would present as a complex fluid collection.

D. This patient does not have the nodular liver contour or heterogeneous echotexture seen in cirrhosis.

E. Pseudoaneurysm is a highly vascular lesion. It is usually the result of trauma or prior intervention.

Question 2

A. Correct! Cavernous hemangiomas are frequently found incidentally on ultrasound, computed tomography, and magnetic resonance imaging examinations. They are the most common benign liver lesion.

Other choices and discussion

B. While large hemangiomas (> 5 cm) can hemorrhage, most cavernous hemangiomas are smaller and do not bleed.

C. Most hemangiomas are asymptomatic and do not affect liver enzyme levels.

D. Consumptive coagulopathy can occur in the setting of Kasabach-Merritt syndrome in infants, but the vast majority of hemangiomas are asymptomatic.

E. This is a benign lesion, so it would not present with metastatic disease.

Question 3

E. Correct! A homogeneous hyperechoic mass is the most common sonographic appearance of a hepatic cavernous hemangioma.

Other choices and discussion

A. Giant and symptomatic hemangiomas can occur, although the majority of cavernous hemangiomas are small (< 5 cm).

B. While some hemangiomas can have flow, that flow is typically slow and may not be visualized on Doppler. In fact, most hemangiomas have no flow on Doppler.

C. Necrosis is not a typical feature of cavernous hemangiomas.

D. Hepatic hemangiomas can have a varied appearance on ultrasound, but most are hyperechoic.

Question 1

A. Correct! A large solid mass is present in the right lobe of the liver. Doppler demonstrates vascular flow within the lesion.

Other choices and discussion

B. Acute hepatitis can present as an enlarged liver with a somewhat hypoechoic hepatic parenchyma. The portal triads remain echogenic, giving the “starry sky” appearance.

C. Abscess presents as a complex fluid collection.

D. Hemangiomas typically present as well-defined hyperechoic masses with no flow on Doppler.

E. Biliary obstruction would cause biliary dilation, which is not seen in this case.

Question 2

C. Correct! Hepatitis E causes acute viral hepatitis and is commonly a co-infection with other viral types. However, it does not predispose to the development of hepatocellular carcinoma (HCC).

Discussion

The other options are incorrect—that is, they are all risk factors for developing HCC. This includes chronic hepatitis B and C, chronic alcohol use, and aflatoxins (fungal toxins used in grains).

Question 3

D. Correct! Fibrolamellar HCC commonly demonstrates internal calcification, which is a distinguishing feature.

Other choices and discussion

A. Fibrolamellar HCC typically presents in patients before the fourth decade of life, and it may occur in adolescents.

B. Fibrolamellar HCC typically presents as a large circumscribed mass lesion and has been reported at > 20 cm in size at the time of diagnosis.

C. Fibrolamellar HCC typically presents as a large solitary mass lesion and is rarely multifocal.

E. Alpha-fetoprotein levels are usually normal in patients with fibrolamellar HCC. Less than 10% of cases have increased levels.

Question 1

A. Correct! Multicystic dysplastic kidney (MCDK) is characterized by multiple, large, noncommunicating cysts that distort the normal renal parenchyma.

B. Correct! Acquired renal cystic disease arises in patients who have undergone chronic dialysis therapy. It is characterized by multiple cysts of varying sizes. The intervening renal parenchyma is shrunken and echogenic.

C. Correct! Autosomal dominant polycystic kidney disease is characterized by numerous cysts. Patients may also have cystic involvement of the liver and pancreas.

Other choices and discussion

D. Lithium toxicity is a cause of cystic renal disease. However, the kidney develops microcysts, which are much smaller than the ones shown in the test case.

E. Renal lymphoma is an infiltrative process presenting as renal enlargement and solid masses that are usually hypoechoic. Cysts are not typical.

Question 2

A. Correct! MCDK is the most common cause of cystic renal disease early in life.

Other choices and discussion

B. Most cases are unilateral with preservation of contralateral renal function.

C. MCDK is characterized by multiple, noncommunicating cysts with a markedly distorted renal parenchyma. The cysts do not communicate with the collecting system, which differentiates this condition from ureteropelvic junction (UPJ) obstruction.

D. MCDK is commonly unilateral. If both kidneys are involved, it can be lethal.

E. Contralateral abnormalities, including vesicoureteral reflux and UPJ obstruction, have been reported in over 25% of patients with MCDK. These contralateral conditions require prompt diagnosis and correction to prevent the progression to renal failure.

Question 3

A. Correct! Screening of the contralateral kidney is indicated. Contralateral abnormalities, including vesicoureteral reflux and UPJ obstruction, have been reported in over 25% of patients with MCDK. These contralateral conditions may impair renal function, and cause hypertension.

Other choices and discussion

B. Because the affected kidney is nonfunctional, percutaneous nephrostomy is not indicated.

C. The collecting system of the nonfunctional kidney often cannot be visualized. Ureteral stent placement would not affect patient outcome.

D. MCDK is typically self-limiting. The cysts and the kidney tend to decrease in size with time.

E. Resection is rarely necessary, usually when when the kidney is massively enlarged.

Question 1

C. Correct! This is pneumobilia. Punctate echogenic foci within the biliary system are seen, consistent with air.

Other choices and discussion

A. Air would not be present within the biliary system in uncomplicated acute cholecystitis. This patient is status post cholecystectomy.

B. Cholangiocarcinoma would demonstrate biliary wall thickening and/or a mass lesion, not air.

D. Hepatic granulomatous disease would present as echogenic foci within the hepatic parenchyma, not within the biliary tree.

E. Polyps are discrete masses, not intraluminal mobile foci.

Question 2

A. Correct! With emphysematous cholecystitis, air collects in the gallbladder wall and may enter the biliary system. Emphysematous cholecystitis is a life-threatening condition and occurs more frequently in diabetics.

B. Correct! Biliary-enteric fistulae are commonly created surgically or can arise spontaneously in the setting of a gallstone ileus. Such fistulae allow air in the bowel to communicate with the biliary tree.

D. Correct! A sphincterotomy is sometimes performed during endoscopy to remove obstructing stones and to image the common bile duct. As a result, air may pass retrograde from the duodenum through the sphincter of Oddi and into the biliary tree.

E. Correct! Acute cholangitis classically presents with the Charcot triad: fever, jaundice, and right upper quadrant pain. Progression of this condition can sometimes lead to pneumobilia. Parasitic infections such as Clonorchis may be responsible. Ultrasound often demonstrates biliary sludge or air. Emergent treatment is necessary to decompress the biliary system.

Discussion

The other choice is incorrect. Mesenteric ischemia is a life-threatening condition seen with necrotic bowel. Air dissects from the necrotic bowel wall into the portal venous system, not the biliary tree. Portal venous gas usually has a more peripheral location on imaging than does biliary air, which is typically located centrally.

Question 3

E. Correct! Immediate surgical intervention is indicated for emphysematous cholecystitis.

The other choices are incorrect.

Question 1

A. Correct! Findings in this case include a nodular, undulating contour of the liver, consistent with cirrhosis. There is also ascites, and the spleen is enlarged.

Other choices and discussion

B. Patients with cirrhosis are at an increased risk for hepatocellular carcinoma (HCC), and thus commonly have screening examinations. However, no mass lesion is present in this case.

C. Acute hepatitis may present as an enlarged liver with diffusely hypoechoic echotexture. The portal triads remain echogenic, giving the “starry sky” appearance.

D. Patients with cholangitis may present with signs of biliary obstruction, including ductal dilation, thickening, and biliary sludge.

E. No masses are seen on this exam.

Question 2

A. Correct! HCC is the most common hepatic malignancy associated with cirrhosis. In the western hemisphere, HCC is commonly associated with chronic hepatitis B and C infections, alcohol use, and cirrhosis.

Other choices and discussion

B. Fibrolamellar carcinoma is a distinct hepatic malignancy that is less common than HCC. It usually occurs in young adults in the second and third decades of life.

C. Angiosarcoma is a rare malignancy that is sometimes associated with toxic agents such as Thorotrast and polyvinyl chloride.

D. Cavernous hemangiomas are the most common benign hepatic neoplasm. The incidence is high, with some studies reporting hemangiomas in up to 20% of the population. These commonly present on ultrasound as small hyperechoic lesions with increased through transmission. They have no malignant potential.

E. Focal nodular hyperplasia is a benign hepatic mass and is more common in females than males. Imaging characteristics often include a central scar on computed tomography and magnetic resonance imaging, early arterial phase enhancement, and delayed uptake on hepatocyte-specific contrast magnetic resonance imaging.

Question 3

E. Correct! Cavernous transformation usually occurs in the setting of longstanding portal venous thrombosis. The characteristic appearance of this condition is the presence of numerous small vessels at the porta hepatis due to collateral circulation.

Other choices and discussion

A. In the setting of portal hypertension or venous occlusion, portal vein flow is away from the liver. This is referred to as retrograde or hepatofugal flow.

B. The main portal vein does not expand with longstanding thrombosis.

C. Malignant thrombosis can be seen in the setting of HCC. However, isolated chronic venous thrombosis does not itself lead to malignancy. Doppler ultrasound can be used to differentiate malignant thrombus (which may have flow) from bland thrombus (which does not have flow).

D. Multiple collateral vessels arise in the setting of longstanding venous occlusion. However, these vessels divert flow away from, not toward, the portal system.

Question 1

D. Correct! This is a pseudoaneurysm. Spectral Doppler performed over the neck of the aneurysm demonstrates flow both above and below the baseline on the Doppler spectrum.

Femoral pseudoaneurysms are commonly iatrogenic and secondary to arterial catheterization.

Other options and discussion

A. No stenosis is seen.

B. Flow is present.

C. A normal peripheral arterial waveform has a rapid upstroke with systole and a lower velocity with diastole. Flow is not normally reversed (unlike the test case, which shows diastolic signal below baseline).

E. A true aneurysm is a dilatation involving all three vascular layers and would not have the waveform shown here.

Question 2

A. Correct! Direct manual compression performed using the ultrasound transducer is a reasonable first-line treatment. It should be performed for approximately 30 minutes.

B. Correct! Ultrasound-guided injection of 1000 units of thrombin into the pseudoaneurysm sac is a reasonable first-line treatment.

Other choices and discussion

C. Covered stent placement is not routinely performed as initial therapy.

D. Surgical re-anastomosis is not routinely performed as initial therapy.

E. Angioplasty is not indicated.

Question 3

C. Correct! The “yin-yang” appearance is typical of a pseudoaneurysm. This appearance results from bidirectional flow in the aneurysm sac with swirling of contents.

Other choices and discussion

A. Velocities are elevated within the pseudoaneurysm.

B. Flow is typically bidirectional with to-and-fro flow through the neck of the pseudoaneurysm.

C. Parvus et tardus waveform is seen in the setting of arterial stenosis, not pseudoaneurysm.

D. Low resistance waveforms are seen with arteriovenous fistulas. These can result from puncture of artery and vein.

Question 1

C. Correct! A solid hypoechoic mass is seen arising from the lower pole cortex. Doppler confirms vascularity in the lesion. This finding on ultrasound should prompt further workup with computed tomography and/or magnetic resonance imaging, and by imaging this is renal cell carcinoma until proven otherwise.

Other choices and discussion

A. A dromedary hump is a contour variant of the renal cortex, which may mimic a mass lesion. The images shown in the test case demonstrate a discrete renal mass. For problem cases, a nuclear medicine renal scan can sometimes be used to confirm normal renal tissue within a dromedary hump.

B. No calculi are visualized. Renal calculi are highly echogenic and often demonstrate posterior acoustic shadowing. When Doppler is applied over a calculus, there is a characteristic “twinkle” artifact.

D. The collecting system is not dilated.

E. An angiomyolipoma is typically a hyperechoic mass on ultrasound.

Question 2

A. Correct! Clear cell is the most common subtype of renal cell carcinoma, accounting for over 70% of cases. Incidence rates of RCC are increased in patients with von Hippel-Lindau syndrome and in the setting of acquired renal cystic disease (seen in patients who have received long-term dialysis).

Other choices and discussion

B. Papillary carcinoma is the second most common subtype and accounts for approximately 10% of RCC. This subtype is typically slower growing and has a more favorable prognosis than clear cell RCC.

C. On computed tomography and magnetic resonance imaging evaluation, chromophobe carcinomas demonstrate less enhancement and have a more favorable prognosis than clear cell RCC.

D. Collecting duct RCC is a rare and aggressive subtype, accounting for < 1% of RCC.

E. Medullary carcinoma is a rare and aggressive subtype, most commonly found in African-American males with sickle cell disease.

Question 3

D. Correct! This is stage III. Renal vein and inferior vena cava invasion are classified as T3. In the absence of distant metastasis, this renders a stage III classification.

Other choices and discussion

There is no in situ classification of RCC. Staging is as follows:

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  Stage I: T1 lesion (≤ 7 cm, limited to the kidney) without nodal or distant metastases

  
  
• 
  

  Stage II: T2 lesion (≤ 10 cm, limited to the kidney) without nodal or distant metastases

  
  
• 
  

  Stage III: T3 lesion without nodal or distant metastases

  
  
• 
  

  Stage IV: T4 lesion (spread beyond Gerota fascia and/or invasion of the ipsilateral adrenal gland), or the presence of distant metastatic disease with any primary lesion