Introduction & Objective: The most common site of involvement in TB is the lungs. TB involves different parts of the lungs and has variable radiologic features. The aim of this study was to compare radiologic sequels between smear positive and smear negative pulmonary tuberculosis patients (PTPs).

Materials & Methods: In an analytic cross-sectional study, 63 pulmonary tuberculosis patients who referred to Farshchian hospital and Health center in Hamadan from March 2012 to September 2014 were enrolled.  Demographic data, clinical manifestations of the patients (smear positive and smear negative), sputum smear results and imaging reports were gathered. In additional, clinical manifestations and radiological findings of the patients were evaluated at the end of the treatment. Thirty two patients remained until the end of the study.

Results: Sixty three patients with mean age 56.85±24.20 were enrolled among that 68.25% of the patients were men and 31.75% were women. Forty four (69.84%) of the patients were smear positive and 19 (30.16%) of them were smear negative. Sputum was seen in smear positive patients more than smear negative patients. At the beginning of the treatment, the most common pulmonary involvements in imaging among the smear positive patients were reported to be nodular infiltration and fibrotic changes, but at the end of the treatment it was found to be atelectasis. However,in the smear negative patients the involvements were alveolar consolidation, nodular infiltration, pleural effusion, ground glass patterns and lymphadenopathy, and at the end of the treatment, fibrotic changes and reduction of pulmonary volume were seen. At the end of the treatment, 54.5% of smear negative patients and 85.7% of smear positive patients had abnormal imaging.

Conclusion: At the end of the treatment, abnormal findings on diagnostic imaging were observed in both smear positive and negative patients (more than 50%). Knowledge of common and various imaging findings in smear positive and smear negative patients can be helpful for early diagnosis of pulmonary tuberculosis.