A randomized trial of spiral CT and ventilation perfusion scintigraphy for the diagnosis of pulmonary embolism

Purpose: To compare spiral computed tomographic pulmonary angiography (SCTA) with lung ventilation-perfusion scintigraphy (VQS) as the initial investigation of patients with suspected pulmonary embolism (PE). Materials and Methods: Prospective randomized trial of 78 patients with suspected pulmonary embolism. Patients underwent either SCTA or lung VQS as their initial investigation for PE. Cross-over between groups meant that 50 patients received both examinations. The clinicians' assessment of overall clinical likelihood of PE was also collected. Results: (1) It was possible to make a confident diagnosis in a significantly larger proportion of patients when SCTA was used as the initial investigation (35/39, 90%) compared with using VQS first (21/39, 54% P