Scintigraphic detection of pulmonary embolism in patients with obstructive pulmonary disease.

Abstract

The 133Xe ventilation (V) studies, 99mTc perfusion (P) lung images and pulmonary angiograms of 83 patients with obstructive pulmonary disease (OPD) and suspected pulmonary emboli (PE) were reviewed. Each patient had ventilation abnormalities suggesting OPD and at least 1 region showing matched V-P abnormalities. All angiograms were obtained within 72 h of the V-P study and were reviewed independently. The overall sensitivity of V-P imaging for PE in this population was 0.83 and its specificity was 0.92. False-negative interpretations occurred in 3 of the 16 patients who showed ventilation abnormalities in > 50% of their lung fields. In the 67 patients with ventilation abnormalities in .ltoreq. 50% of their lung fields, the sensitivity (0.95) and specificity (0.94) for detecting PE were high. If the ventilation abnormalities are limited in extent, V-P imaging is a reliable method for detecting PE in patients with regions of V-P match.