Pulmonary sarcoidosis: role of CT in the evaluation of disease activity and functional impairment and in prognosis assessment.

Objective: To investigate the role of computed tomography (CT) in determining disease activity and functional impairment and in predicting the prognosis of lung involvement in patients with sarcoidosis.

Methods: Two groups of patients underwent CT, pulmonary function tests, and bronchoalveolar lavage. Disease activity was based on serum angiotensin converting enzyme activity and/or lymphocytosis at bronchoalveolar lavage. CT findings in group 1 were correlated with indexes of disease activity and functional parameters at diagnosis. In group 2, evaluation initially and at follow-up led to investigation of correlations between initial CT findings and evolution of disease activity and functional impairment.

Results: CT abnormalities in group 1 were nodules, air-space consolidation, lung distortion, septal and nonseptal linear areas of high attenuation, ground-glass attenuation, and honeycombing. Profusion of septal lines was the only CT finding that correlated with disease activity. Statistically significant (P < .05) but low correlation (r < .48) was observed between the extent of abnormalities at CT and impairment of lung function, except for nodules.

Conclusions: Profusion of lung changes reflects functional impairment but not disease activity. CT findings cannot help predict the evolution of lung changes over time.