[Computerized tomography imaging of round atelectasis. Study of a series of 21 patients]

To show and compare to literature CT findings in round atelectasis.

It is a retrospective review of the clinical and radiological files of 21 patients (17 men; 4 women; Mean age: 62), having asbestos exposure (6/21) or pleural history (13/21) and in whom the diagnosis of round atelectasis was performed from 1988 to 1998. This diagnosis was based on the presence of the classical radiological triad: round mass abutting to pleurae, converging bronchovascular markings and pleural thickening adjacent to the mass associated at a one year follow up or three years radiological and clinical follow up or the association with three minors radiological signs.

The 25 round atelectasis, 4 bilateral, were localized in the lower lobes (22/25) or upper lobes (3/25) at right (17/25) or left (8/25) side. Minor signs were found as in literature as followed: air bronchograms and centrally indistinct margin (25/25, diffused pleural thickening or pleural plaques (19/25), acute angles with the pleura (18/25), fissures displacement (18/25), main stem bronchus displacement (13/25), calcifications within the plaque (10/25), calcifications within the mass (10/25). A mean of 6.7 signs was found for each lesion.

More than the major signs of round atelectasis the air bronchogram, the centrally indistinct margin and the presence of one sign of retraction were very frequent. The mean number of signs was 6.7 for every lesion.