A 29-year-old woman, G2P1, at 24 weeks gestation presents to the emergency department with sudden-onset shortness of breath and right-sided pleuritic chest pain. Her heart rate is 112/min, respiratory rate is 22/min, blood pressure is 110/70 mmHg, and oxygen saturation is 94% on room air. Physical examination reveals clear lungs bilaterally, normal heart sounds, and no asymmetric lower extremity edema, erythema, or tenderness. An electrocardiogram shows sinus tachycardia. You are planning the diagnostic pathway to evaluate for a suspected pulmonary embolism while minimizing fetal and maternal radiation exposure.
Arrange the following diagnostic modalities in the correct sequential order as recommended by current clinical guidelines, proceeding to the next step only if the preceding test is negative, normal, or non-diagnostic.
- 1Chest radiograph
- 2Bilateral lower extremity compression ultrasonography
- 3Ventilation-perfusion (V/Q) scan
- 4Computed tomography pulmonary angiography (CTPA)