Atypical mycobacterial infection in the lung: CT appearance

The author examined computed tomographic (CT) scans of the chest from 40 patients with cultures positive for atypical mycobacteria. Common manifestations included bronchiectasis, air-space disease, nodules, and scarring and/or volume loss. Less commonly observed signs were cavities, lymphadenopathy, and pleural disease. Serial scans were obtained in 10 patients and showed new areas of bronchiectasis and progression of existing bronchiectasis, suggesting that the bronchiectasis was not a preexisting condition but resulted from infection. The anatomic distribution of the above findings was diffuse, not strongly favoring any lung zone. The identification of multifocal coexistent bronchiectasis, air-space disease, and nodules at CT should raise the possibility of atypical mycobacterial lung disease, even in an otherwise healthy patient.