Abstract: Objective To analyze the CT features of non-tuberculous mycobacterial pulmonary disease and improve the cognition about it. Methods 42 cases of Non-tuberculous Mycobacteria infected patients diagnosed by sputum, bronchial washings fluid or pathological tissue culture and species identification were identified as observation group, and 42 patients with mycobacterium tuberculosis culture positive were selected as control group. The distribution, location, morphology and nature of the lesions in the two groups were compared.Results Lesions were widely distributed in the observation group, and the rate of lesion involvement in one lung lobe was 21.43%, lower than 45.24% in the tuberculosis group, with statistically significant differences (χ²=5.36, P<0.05). The rate of lesions involving 3 or more pulmonary lobes in the observation group (50.00%) was higher than that in the tuberculosis group (26.19%), and the difference between the two groups was statistically significant (χ²=5.05, P<0.05). In the non-tuberculous mycobacterial pulmonary disease group, the detection rate of lesions in the middle lobe and tongue segment was 78.57%, which was higher than 30.9% in the tuberculosis group, and the difference between the two groups was statistically significant (χ²=19.2, P<0.05). The incidence of bronchiectasis, thin-walled cavities, and emphysema bullous blisters in non-tuberculous mycobacterial pulmonary disease group was 54.76%, 23.81%, and 28.57%, which were higher than those of tuberculosis group (19.05%, 7.14%, and 9.52%, respectively). The difference between the two groups was statistically significant (χ²=11.50, 4.46 and 4.94, all P<0.05). The incidence of bronchial diffusion, calcification, glassed shadow, pleural effusion and mediastinal lymph node enlargement in non-tuberculous Mycobacterial pulmonary disease group was 9.52%, 16.67%, 9.52%, 11.90% and 16.67%, which were lower than that of the tuberculosis group (40.48%, 40.48%, 33.33%, 30.95% and 35.71%, respectively), and the differences were statistically significant (χ²=10.73, 5.83, 7.07, 4.53 and 3.94, all P<0.05). There was no statistically significant difference in the incidence of thick-walled cavities, infiltrating lesions, proliferating nodules and fibrous cords between the two groups (P>0.05). Conclusion The chest CT findings of non-tuberculous mycobacteria pulmonary disease are characterized by a wide distribution, two lungs scattered in columnar dilated bronchi, obvious lesions in the middle lobe of the right lung and the tongue segment of the left lung, subpleural thin-wall cavity and surrounding cavity with columnar bronchodilation, common emphysema and pulmonary bullae, etc.

Key words: Non-tuberculous mycobacteria, Tuberculosis, Tomography, X-ray computed