Comparison of conventional pulmonary angiography with intravenous digital subtraction angiography for pulmonary embolic disease.

Intravenous digital subtraction pulmonary angiography was performed in 33 patients with suspected pulmonary embolism. It was performed as the initial examination, followed immediately by conventional film-screen pulmonary angiography performed with selective right or left main pulmonary injections. Intravenous studies of diagnostic quality were obtained in 31 of 33 patients (93.9%). Of the satisfactory intravenous studies, pulmonary embolism was correctly diagnosed in 12 cases and excluded in 18 cases. Emboli were detected in major and second-order branches, and occasionally in third-order branches as well. There was one false-positive intravenous pulmonary study, but the overall accuracy was 90.9% considering all studies and 96.8% excluding the two inadequate intravenous examinations. It is concluded that intravenous pulmonary angiography is an acceptable substitute for routine pulmonary angiography in most patients with suspected major pulmonary embolism. The technique is less expensive, and is safer, faster, and easier to perform than conventional pulmonary angiography.