Background: The aim of this study was to describe the signs of active tuberculosis in patients submitted to high resolution computerized tomography and the distribution of lesions along the pulmonary parenchyma. Material and methods: The high resolution CTs performed on 42 patients with tuberculosis either bacteriologically diagnosed or clinical suspected and later confirmed by bacteriological tests were studied. Results: The signs of disease activity observed were airspace nodule (83%), centrilobular nodule (74%), tree-in-bud pattern (67%), cavitations (67%), bronchial thickening (55%), parenchymal consolidations (48%), ground glass opacity (21%) and thickening of the inter and intralobular septa (9%). Conclusion: High resolution computed tomography can be strongly suggestive of disease activity, is particularly helpful in patients with negative smear and/or undetermined radiographs, and allows the establishment of proper treatment, even before mycobacteria are identified in means of culture.

Keywords: Pulmonary tuberculosis. X-ray computed tomography.