The chest radiograph in Legionnaires' disease. Further observations.

Chest radiographs of 70 patients with Legionnaires' disease were evaluated and compared to the authors' previous series of 24 patients as well as others in the literature. A larger number of patients in the more recent survey had pleural effusion, and there were 3 with cavitation whereas none was seen previously. Analysis of the radiograph showing the most marked changes in survivors versus patients who died showed no consistent pattern, indicating that the radiograph cannot be used as a prognostic indicator. On long-term follow-up (mean, 104.2 days), the radiograph remained abnormal for many months and demonstrated a variety of slowly resolving or permanent abnormalities.