Computed tomography in pulmonary sarcoidosis.

A group of 34 proven cases of pulmonary sarcoidosis was investigated by computed tomography (CT) to determine whether CT provided any information beyond that obtained from conventional chest films. Computed tomography disclosed a surprisingly high prevalence of minor pleural changes in sarcoidosis, including two patients with small pleural effusions. Unsuspected bullae and isolated "granulomatous" nodules were additionally demonstrated. Increases in lung density and alterations in gravity dependent vascular perfusion were assessed; these may reflect alterations in the vascular bed, and the increased density is possibly due to diffuse invasion of the lung not recognizable by conventional chest X-ray films. Tracheal compression was noted in one case and vertebral densities in three. Prominence of "small air spaces" was recorded in four patients; the nature of the pathology responsible for this finding is at present speculative. While not replacing conventional chest radiography, CT does make a definite contribution to the assessment of pulmonary sarcoidosis.