SPEX SPEX Radiology and Imaging 2 — Questions and Answers
Question 1: Which finding on ultrasound is most consistent with acute cholecystitis?
- Hyperechoic bile with shadowing
- Gallbladder wall thickening with a positive Murphy's sign on US (Correct answer)
- Dilated common bile duct only
- Intrahepatic biliary dilation
Correct answer: Gallbladder wall thickening with a positive Murphy's sign on US
Sonographic Murphy's sign (probe tenderness over the gallbladder) combined with wall thickening >4 mm is highly specific for acute cholecystitis.
Question 2: What is the most appropriate imaging for a pregnant woman with suspected appendicitis when ultrasound is inconclusive?
- CT abdomen and pelvis without contrast
- MRI abdomen without contrast (Correct answer)
- Plain abdominal X-ray
- Nuclear medicine scan
Correct answer: MRI abdomen without contrast
MRI without contrast is preferred in pregnancy for inconclusive ultrasound findings because it avoids ionizing radiation while providing excellent soft tissue detail.
Question 3: A bone scan shows a 'cold' lesion in a patient with known multiple myeloma. What does this indicate?
- Active bone metastasis
- Osteomyelitis
- Avascular necrosis
- Aggressive lesion with poor blood flow (Correct answer)
Correct answer: Aggressive lesion with poor blood flow
Cold lesions on bone scan represent areas of poor vascularity; in myeloma, purely lytic lesions may not take up the tracer, making plain X-rays or PET-CT superior.
Question 4: Which finding on echocardiography is most consistent with cardiac tamponade?
- Left ventricular hypertrophy
- Right ventricular diastolic collapse (Correct answer)
- Mitral valve prolapse
- Aortic stenosis with gradient >40 mmHg
Correct answer: Right ventricular diastolic collapse
Right ventricular diastolic collapse on echo is a hallmark of cardiac tamponade, indicating elevated pericardial pressure compressing the right heart.
Question 5: Which imaging modality best characterizes liver lesions detected incidentally on CT?
- PET scan
- Plain abdominal X-ray
- MRI with hepatobiliary contrast agent (Correct answer)
- Technetium-labeled RBC scan
Correct answer: MRI with hepatobiliary contrast agent
MRI with hepatobiliary contrast agents (e.g., gadoxetate disodium) provides excellent characterization of focal liver lesions including hemangiomas, HCC, and metastases.
Question 6: What is the Westmark sign on chest X-ray in the context of pulmonary embolism?
- Wedge-shaped peripheral opacity
- Focal oligemia distal to an occluded vessel (Correct answer)
- Enlarged pulmonary artery
- Pleural effusion on the affected side
Correct answer: Focal oligemia distal to an occluded vessel
Westermark sign refers to focal oligemia (decreased vascular markings) distal to an obstructing embolus, indicating reduced perfusion.
SPEX SPEX Radiology and Imaging 2
Which finding on ultrasound is most consistent with acute cholecystitis?