Radiographic assessment of perfusion impairment in pulmonary embolism.

To assess whether radiographic features of descending pulmonary artery reflect the severity of the vascular obstruction we reviewed chest radiographs and perfusion lung scans in 115 patients affected by pulmonary embolism. Patients were classified according to the radiographic appearance of the descending pulmonary artery: normal, enlarged, and markedly enlarged with "sausage" shape. At acute embolization, patients with "sausage" appearance of the artery had the most serious vascular obstruction (56% on the average), in respect to patients with simply enlarged arteries (39% obstruction on the average, p less than 0.001) and patients with normal arteries who had the smallest obstruction (26% on the average, p less than 0.001). At recovery, patients showed a parallel decrease of descending pulmonary artery width and vascular obstruction.