[Computed tomography in the differential diagnosis of disseminated pulmonary tuberculosis and fibrosing alveolitis].

The differential diagnostic signs of disseminated pulmonary processes were defined by computed tomography. A hundred and sixty-seven patients, including 117 (70%) with disseminated pulmonary tuberculosis (DPT) and 50 (30%) with alveolitis, were examined. Their mean age was 32.3 +/- 5.1 years; the history of disease averaged 4.6 +/- 1.2 years. Acute, subacute, and chronic DPT was observed in 17 (14.5%), 32 (27.3%), and 68 (58.1%) patients, respectively. Idiopathic fibrosing alveolitis (IFA) was seen in 38 patients; 12 patients had exogenous allergic alveolitis (EAA). IFA and EAA were chronic. Patients with DPT had most commonly signs, such as focal masses (45.3%), intra- and interlobular septal thickening (35%), lung tissue reticulation (35%), centrilobular empyema (29%), only focal masses being detected in its acute form, and other signs being more pronounced in its subacute and particularly chronic form. Glassy dark patches, the opal glass syndrome, were a common sign in patients with alveolitis. Septal thickening, lung tissue meshwork, and centrilobular emphysema were encountered only in patients with IDA and small-nodular focal masses and bronchial wall thickening were present in those with EAA.