Pulmonary Embolism USMLE Step 1 Practice Question
A 52-year-old man with a 10 pack-year smoking history presents to the emergency department with acute onset dyspnea and pleuritic chest pain for 3 hours. He reports no leg swelling or pain. Vital signs: HR 118/min, BP 128/82 mmHg, RR 22/min, SpO2 89% on room air. Physical examination reveals clear lung fields bilaterally. Chest X-ray shows a wedge-shaped consolidation in the right lower lobe with a small pleural effusion. Laboratory studies reveal D-dimer 2.8 μg/mL (elevated), troponin I 0.08 ng/mL (normal), and normal hemoglobin and white blood cell count. ECG shows sinus tachycardia with no ST changes. He is taken for contrast-enhanced CT angiography of the pulmonary arteries. Which of the following findings is most consistent with the clinical presentation?
Answer choices
- ALack of pulmonary artery opacification with normal right ventricular size
- BFilling defect within the right lower lobe pulmonary artery with Hampton's hump consolidationCorrect answer
- CPulmonary trunk filling defect with acute right ventricular dilatation and right atrial enlargement
- DPeripheral ground-glass opacities in bilateral lower lobes with pulmonary edema pattern
- EBronchial wall thickening and bronchiectasis with preserved pulmonary artery caliber
- FMediastinal and hilar lymphadenopathy with patent pulmonary arteries
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.