Abstract
Clinical diagnosis of pulmonary embolus (PE) is difficult. Pulmonary angiography is still the gold standard for diagnosing PE, and ventilation perfusion (VQ) lung scans are used as a screening test. With normal VQ scans, PE can be ruled out. High probability VQ scans have high positive accuracy. The authors conducted a retrospective analysis of 45 patients who underwent intermediate VQ scans. Of the 45 patients who had intermediate VQ scans performed, 37 (82%) had venous duplex imaging (VDI) conducted, with 7 found to be positive for deep vein thrombosis. Of the 45 patients who had intermediate VQ scans performed, 12 (27%) had pulmonary angiograms performed, 7 (58%) of which were positive for PE. Six of these seven patients also had VDI conducted, all of which were negative. In total, of the 22 patients found to have a clinical discharge diagnosis of PE, 13 had either VDI studies or pulmonary angiographies positive for PE. These results indicate that a positive VDI study substantiates a diagnosis of PE. However, negative VDI study does not rule out pulmonary embolus.