Suspected pulmonary embolism: prevalence and anatomic distribution in 487 consecutive patients. Advances in New Technologies Evaluating the Localisation of Pulmonary Embolism (ANTELOPE) Group.

Abstract

To evaluate the prevalence and anatomic distribution of pulmonary embolism (PE) in a group of consecutive patients clinically suspected of having PE. Four hundred eighty-seven consecutive patients clinically suspected of having PE were examined in six Dutch hospitals from May 1997 through March 1998. Patients underwent ventilation-perfusion (V-P) scintigraphy, spiral computed tomographic (CT) angiography, and/or digital subtraction pulmonary angiography according to a strict diagnostic protocol. Independent readers reviewed all of the diagnostic image studies in centralized readings. The largest pulmonary arterial branch in which PE was detected was recorded. The prevalence of PE was 27% (130 of 487 patients). There was a significant difference in PE size between the high-probability and nondiagnostic V-P scans: The high-probability scans tended to depict larger emboli, but they also showed small subsegmental emboli. Twenty-nine (22%) of 130 patients had subsegmental PE; 23 of these 29 patients had a high-probability V-P scan. The largest pulmonary arterial branch with PE was central or lobar in 66 (51%), segmental in 35 (27%), and isolated subsegmental in 29 (22%) patients.