Abstract: Objective To investigate the CT features and charac-teristics of relapsing patients with old pulmonary tuberculosis,and to provide evidence for its early diagnosis. Methods A total of 100 patients with old pulmonary tuberculosis in Guangzhou Chest Hospital diagnosed by clinical and laboratory from April 2009 to December 2019 were collected, among which 40 patients with reburning were reburning group and 60 patients without reburning were nonreburning group. The CT features of the two groups were compared and analyzed, and the CT features of relapsing patients with old pulmonary tuberculosis were summarized. Results The incidence of pulmonary lesion involving lobes of both lungs in reburning group and nonreburning group was 22.50%（9/40）and 65.00%（39/60）, 60.00%（24/40）and 25.00%（15/60）, 17.50%（7/40）and 10.00%（6/60）22.50%(9/40), respectively. There were significantly difference between the two groups(χ² values:17.37, 12.36 and 5.32, respectively;P value：<0.0001,0.0004 and 0.0211, respectively). The detection rate of clear margin, calcification, hilar mediastinal lymph nodes and pleural thickening was compared between the two groups, there were no significant differences (χ² values: 2.025, 3.255, 0.0071 and 0.0631, respectively;P values:0.1548, 0.0712, 0.9330 and 0.8017, respectively). There were significantly difference in the detection rate of imaging signs of bronchial tuberculosis, consolidation and Cavitation, bronchiectasis, pulmonary bullae (χ² values: 4.438, 6.250, 4.001 and 3.177,respectively;P value：0.0351, 0.0124, 0.0455 and 0.0015, respectively). Conclusion CT scan of patients in the reburning group showed a wide range of pulmonary lesions, and the incidence of pulmonary lesions combined with bronchial tuberculosis consolidation, cavity bronchial dilatation and pulmonary bullae was higher than that in the nonreburning group, Which can make a contribution for early clinical diagnosis and treatment.

Key words: Old pulmonary tuberculosis, Relapsed, Tomography, spiral computed, Disease attributes