Serial lung scintigraphy: utility in diagnosis of pulmonary embolism.

Publisher Website
Google Scholar
Abstract
Pairs of sequential perfusion lung scans and pulmonary angiograms obtained in 45 patients were reviewed to investigate the utility of short-term, sequential scintigraphy in the diagnosis of pulmonary embolism (PE). Sequential scan pairs (46) were reviewed; 13 were ventilation-perfusion (V-P) pairs. Angiograms were obtained within 48 h of either the 1st (65%) or 2nd (35%) perfusion scan in each pair. Sequential scintigraphic patterns were classified as showing change (i.e., improvement in defects, new defects), no change or as being indeterminate. A changing perfusion pattern was associated with a high (20/23) likelihood of PE, but 7 of 16 patients with stable perfusion patterns also had PE. The sensitivity of a changing perfusion pattern for PE was 0.74 (20/27) and its specificity was 0.75 (9/12). In 2 of 6 patients who had serial V-P studies that showed changing perfusion defects, there were matched changes in regional ventilation and angiograms were negative. Evidently, short-term serial perfusion lung scanning may aid the scintigraphic diagnosis of PE in certain circumstances. Serial V-P imaging is needed, however, to maximize diagnostic specificity.