A 55-year-old man with a history of hypertension and hyperlipidemia presents to the ED with sudden-onset pleuritic chest pain and dyspnea. He recently completed a transatlantic flight. His vital signs show HR 110/min, BP 130/80 mmHg, RR 28/min, SpO2 90% on room air. ECG shows sinus tachycardia. What is the most appropriate initial diagnostic test?
✓ Correct Answer: Option C
Given the high suspicion for pulmonary embolism (sudden pleuritic chest pain, dyspnea, risk factors like recent long flight, and hypoxemia), CT pulmonary angiography is the gold standard for diagnosis and is indicated as the initial imaging study.