Pulmonary septic emboli: diagnosis with CT

The CT scans of 18 patients with documented pulmonary septic emboli were reviewed. CT features of septic emboli included multiple peripheral nodules ranging in size from 0.5 to 3.5 cm (15 of 18 patients [83%]), a feeding vessel sign (n = 12; [67%]), cavitation (n = 9; [50%]), wedge-shaped peripheral lesions abutting the pleura (n = 9 [50%]), air bronchograms within nodules (n = 5 [28%]), and extension into the pleural space (n = 7 [39%]). In six of the 18 patients, CT was the first modality (before radiography) to show lesions compatible with septic emboli. In five clinically unsuspected cases, CT first suggested the correct diagnosis of septic emboli. In eight patients, CT also enabled identification of more parenchymal lesions, presumed to be septic emboli, and more pleural involvement than chest radiographs, thus demonstrating a greater extent of disease. The authors conclude that CT is an important modality for confirming the presence of pulmonary septic emboli even when conventional chest radiographs remain negative. In the proper clinical setting, characteristic CT features of septic emboli can suggest the correct diagnosis.