Journals of

Background and Aim: Tuberculosis is a chronic lung infection that has contaminated 1/3 of men worldwide and nowadays causes 2 million deaths and 9 million diseases. One of the can be can be assisted tests, in addition to smear, in the diagnosis of pulmonary tuberculosis is lung radiography. In tuberculosis patients radiography of negative smear samples, which is often diagnosed with delay, can be assisted. In the present study, radiographic changes of tuberculosis patients with positive smear and those with negative smear have been compared. Materials and Methods: In this descriptive, retrospective, and analytical study, out of 376 patients who had exactly been diagnosed as tuberculosis ones and had been referred to Birjand health center during 2001-2006. One hundred patients whose smear tests were positive, according to WHO's standards, were selected .Then, among negative smear patients 100 individuals who were demographically compatible with positive smear ones were chosen. All of them had x-rays from their lungs, which were then interpreted by a radiologist. Moreover, all patients' sputum tests were done in the reference lab of the Health Center under a technician. The obtained data was analyzed by means of frequency distribution table and descriptive statistics using SPSS (version 15) and Chi-square statistical test. Results: Except reticulunoduler infiltration, relative frequency of other radiographic findings in positive smear patients was more than negative smear ones and only in the variables calcification, adenopathy of the lungs hilum, mediastinal widening, and patchy infiltration the difference was statistically significant P<0.05. Conclusion: Regarding the results of the study, although radiographic changes are not decisive in the diagnosis of pulmonary tuberculosis if they are accompanied by clinical symptoms and sputum smear, they can be assisted.