Abstract:

Objective To investigate the similarities and differences of imaging features between nontuberculous mycobacterial (NTM) lung diseases and pulmonary tuberculosis(PTB).Methods CT features of 74 inpatients from Jan,2012 to Dec,2017 with pulmonary NTM infection were retrospectively analyzed and compared with that of 100 case with PTB in random selection in the corresponding period. The sites and morphological features of the lesion were analyzed.SPSS 17.0 software was used, count data using χ ² test. P<0.05 was considered to be statistically different.Results Comparing the image types of the two group, nodular bronchiectsis type in NTM group (51.4%,38/74)were more than in tuberculosis group(14.0%,14/100), there was a significant difference between the two groups (χ ²=28.316, P=0.000), the nodular/mass type in tuberculosis group (21.0%,21/100)was more than that in the NTM group(8.1%,6/74), there was a significant difference between the two groups(χ ²=5.392,P=0.020). The dominant sites in the upper lobe of pulmonary tuberculosis(82.0%,82/100)was more than that of NTM group (59.5%,44/74), there was a significant difference(χ ²=10.817,P=0.001). The detection rate of NTM in middle lobe of right lung and (or)pulmonary lingual segment (16.2%,12/74) was higher than that of pulmonary tuberculosis (5.0%,5/100),there was a significant difference(χ ²=6.069,P=0.014);and the detection rate of bronchiectasis of tuberculosis group(61.0%,61/100) was less than that of NTM group(93.2%,69/74);the dominant sites of bronchiectasis in NTM group(39.1%,27/69) in middle lobe and(or)pulmonary lingual segment was more than that of pulmonary tuberculosis group (13.1%,8/61)(χ ²=11.138,P=0.001),the dominant sites of bronchiectasis in pulmonary tuberculosis group (70.5%,43/61)in upper lobe was more than that of NTM group (39.1%,27/69) (χ ²=12.813,P=0.000),the detection rate of consolidation in pulmonary tuberculosis group(86.0%,86/100) was higher than that of NTM group (67.6%,50/74)(χ ²=8.465,P=0.004),the subpleural cavity in NTM group(95.1%,39/41) was significantly more than that in pulmonary tuberculosis group(61.8%,42/68)(χ ²=14.909,P=0.000);There were differences in the size of nodules in the lung between two groups, nodules <1cm were more common in NTM group(88.5%,54/61)than that in pulmonary tuberculosis group (54.9%,50/91),there was a significant difference(χ ²=19.059.P=0.000),various size nodules was more common in PTB group(41.9%,29/91) than that in NTM group(8.2%,5/61),there was a significant difference(χ ²=11.784.P=0.001).In addition the detection rate of complicated pleural effusion in pulmonary tuberculosis group(34.0%,34/100)was higher than that of NTM group(20.3%,15/74), there were signifcant differences(χ ²=3.963, P=0.047). Conclusion Chest HRCT image features are similar in NTM lung disease and PTB, but there are differences.The image classification,the distribution and dominant sites of bronchiectasis, the incidence of consolidation and the size of nodules may be helpful to differential diagnosis. The detailed analysis of image features and closely combining with the clinical data can be helpful to diagnosis.

Key words: Mycobacterium infections, Tuberculosis, pulmonary, Tomography, X-ray computed, Diagnosis, differential, Disease attributes, Data interpretation, statistical