title: Serial lung scintigraphy: utility in diagnosis of pulmonary embolism.
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). Forty-six sequential scan pairs were reviewed; 13 were ventilation-perfusion (V-P) pairs. Angiograms were obtained within 48 hours of either the first (65%) or second (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 seven 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 two of six patients who had serial V-P studies that showed changing perfusion defects, there were matched changes in regional ventilation and angiograms were negative. The findings suggest that 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.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D012709:Serum Albumin; D013667:Technetium; D013668:Technetium Tc 99m Aggregated Albumin; D013997:Time Factors; D014692:Ventilation-Perfusion Ratio
chemical_list: D012709:Serum Albumin; D013668:Technetium Tc 99m Aggregated Albumin; D013667:Technetium