A 32-year-old woman at 24 weeks gestation presents to the emergency department with sudden-onset shortness of breath and pleuritic chest pain. Her heart rate is 115/min, respiratory rate is 24/min, and blood pressure is 110/70 mm Hg. Physical examination reveals mild right leg swelling and tachycardia but normal breath sounds bilaterally. Clinical suspicion for a pulmonary embolism (PE) is high. Arrange the following diagnostic imaging studies and their corresponding findings in the most appropriate chronological sequence for safely and definitively evaluating this patient.
- 1Bilateral lower extremity compression ultrasonography yielding a negative result for deep vein thrombosis.
- 2Posteroanterior and lateral chest radiography demonstrating clear lung fields without consolidation or pneumothorax.
- 3Ventilation-perfusion (V/Q) scan interpreted as indeterminate probability for pulmonary embolism.
- 4Computed tomography pulmonary angiography (CTPA) confirming a segmental filling defect in the right lower lobe pulmonary artery.
Cevap
The correct chronological sequence is: 1) Bilateral lower extremity compression ultrasonography, 2) Chest radiography, 3) Ventilation-perfusion (V/Q) scan, and 4) Computed tomography pulmonary angiography (CTPA).
The evaluation of suspected pulmonary embolism in pregnancy strictly adheres to a step-wise algorithm designed to minimize ionizing radiation. The initial imaging test of choice is bilateral lower extremity compression ultrasonography, especially when leg symptoms are present. If a deep vein thrombosis is identified, anticoagulation is initiated, and thoracic imaging can be safely deferred. If ultrasonography is negative, a chest radiograph is performed to evaluate for alternative etiologies and to guide the selection of subsequent pulmonary imaging. With a normal chest radiograph, a ventilation-perfusion (V/Q) scan is preferred over CTPA because it delivers a markedly lower radiation dose to the maternal breasts. CTPA is reserved as the final definitive step only when the V/Q scan returns an indeterminate or non-diagnostic result.
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Anahtar Kavram
The step-wise diagnostic imaging algorithm for suspected pulmonary embolism in pregnancy aims to minimize radiation exposure to the fetus and maternal breast tissue.