Utilization patterns and diagnostic yield of 3421 consecutive multidetector row computed tomography pulmonary angiograms in a busy emergency department

Objective: To compare examination volume and diagnostic yield of computed tomography (CT) pulmonary angiography (CTPA) and ventilation-perfusion (V/Q) scintigraphy for detection of suspected pulmonary embolism (PE) in emergency department patients. Methods: Every CTPA and V/Q scan result for emergency department patients between October 2001 and September 2005 were reviewed. Patients with prior PE and follow-up examinations were excluded. Results: A total of 3421 CTPA examinations and 198 V/Q scans met inclusion criteria. Average CTPA examinations completed per month increased 227%, from 33.4 to 109.2 for the first and last 24-month periods, respectively. Ventilation-perfusion scintigraphy volume decreased 80% (from 6.9 to 1.4 per month). Total diagnoses of PE per month increased 89% from 4.0 to 7.5, whereas the percentage of positive CTPA examinations dropped from 9.8% to 6.8%. Conclusions: Availability of CT in the emergency department and lower physician thresholds for test utilization have increased the use of CT pulmonary angiography and increased detection of PE.