Pulmonary Embolism USMLE Step 1 Practice Question
A 38-year-old primigravida at 12 weeks gestation presents with acute dyspnea and pleuritic chest pain. Vital signs show BP 128/82 mmHg, HR 118/min, RR 22/min, SpO2 88% on room air, and temperature 37.2°C. She denies leg swelling or calf pain. Bilateral lower extremity compression ultrasound is negative for DVT. Chest X-ray shows clear lung fields. D-dimer is elevated at 850 ng/mL. Which diagnostic study is most appropriate to evaluate for PE in this patient?
Answer choices
- AObservation with serial troponin measurements
- BVentilation-perfusion scanCorrect answer
- CMagnetic resonance pulmonary angiography
- DCTPA with radiation dose reduction protocol
- ED-dimer testing to exclude PE
- FPulmonary angiography with catheter-based contrast injection
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