How accurate are ventilation-perfusion scans for pulmonary embolism?
To evaluate the accuracy of ventilation-perfusion scanning in the diagnosis of pulmonary embolism, the pulmonary arteriograms of 55 patients suspected of pulmonary embolism were compared with their ventilation-perfusion scans. The clinical presentation was consistent for the diagnosis of pulmonary emboli in all 55 patients. The scans were divided into the following four categories according to standard guidelines: normal, low, intermediate, and high probability. Three patients had normal scans confirmed by arteriography; 34 patients had high-probability scans, but only 22 (65 percent) were positive at arteriography. The remaining 18 patients had low or intermediate-probability scans (9 patients each), 5 of whom (28 percent) were positive at angiography (sensitivity 82 percent, specificity 57 percent). This study demonstrates the inaccuracy of ventilation-perfusion scanning for the evaluation of pulmonary embolus and may represent the variability of interpretation at individual institutions. Perhaps each institution may need to compare the results of ventilation-perfusion scanning and angiography to optimally select and treat patients.
Caracci
B F
BF
Department of Surgery, St. Louis University Medical Center, Missouri 63104.
Rumbolo
P M
PM
Mainini
S
S
Walker
H S
HS
Peterson
G J
GJ
D000328:Adult; D000368:Aged; D000792:Angiography; D000925:Anticoagulants / Q000627:therapeutic use; D006801:Humans; D008168:Lung / Q000098:blood supply; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000188:drug therapy; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014692:Ventilation-Perfusion Ratio
D000925:Anticoagulants