A 62-year-old man presents to the emergency department with sudden onset dyspnea, pleuritic chest pain, and a cough productive of blood-tinged sputum. He recently completed a transcontinental flight. His oxygen saturation is 90% on room air. Physical exam shows tachypnea and tachycardia. Which of the following is the most appropriate initial diagnostic study?
✓ Correct Answer: Option C
Given the high pre-test probability for pulmonary embolism (PE) based on symptoms (dyspnea, pleuritic chest pain, hemoptysis) and risk factors (long flight), CT pulmonary angiography is the gold standard and most appropriate initial diagnostic test to confirm or exclude PE rapidly.