Abstract:

Objective To analyze the CT image classification of non-tuberculosis mycobacterium(NTM) pulmonary disease and the clinical and CT features in patients with different CT image classifications. Methods The clinical and CT data of 132 patients with non-tuberculous mycobacterial pulmonary disease admitted in Beijing Chest Hospital, Capital Medical University from November 2011 to January 2018 were analyzed retrospectively. According to CT imaging features, there were four types of cavities in the upper lobe, nodular bronchiectasis, mixed and difficult to differentiate. The clinical and imaging characteristics of patients with different image classification were analyzed statistically using SPSS software with 17.0 version, and the enumeration data were analyzed by chi-square test or continuous correction chi-square test. Measurement data were analyzed by t test or variance analysis. The difference were considered statistically significant when P<0.05. When the clinical statistical data of 4 groups of patients with different types of patients were compared in pairs, P<0.008 was considered as the significant statistically difference. Results Of 132 cases with non-tuberculous mycobacterial pulmonary disease, there were 36 (27.3%) cases in the type of upper lobe cavitary 61 (46.2%) cases in the type of nodular bronchiectasis, 15 (11.4%) cases in the mixed type and 20 (15.2%) cases in unclassified type. The male ratio from high to low were upper lobe cavitary (86.1%, 31/36), unclassified type (70.0%, 14/20), mixed type (53.3%, 8/15) and nodular bronchiectasis (24.6%, 15/61) in all cases with significant statistically difference (χ ²=37.712,P<0.001).The average age of patients with upper lobe cavitary, nodular bronchiectasis, mixed type and unclassified type were 58.5±13.8, 58.1±13.3, 64.3±10.4 and 51.0±17.0 years old with no significant difference (F=1.875, P=0.140). The ratio of smoker in patients with upper lobe cavitary (64.7%,22/34) was significantly higher than that in patients with nodular bronchiectatic type (13%, 7/54)(χ ²=25.258, P<0.001). The incidence rate of emphysema (66.7%,24/36) and interstitial fibrosis (33.3%,12/36) in patients with upper lobe cavitary were significant higher than those (13.1%,8/61 and 0.0%,0/61) in patients with nodular bronchiectasis (χ ²=29.369,P<0.001;χ ²=23.204,P<0.001). The incidence rates of pleural thickening in upper lobe cavity type (61.1%, 22/36) and in mixed type (66.7%,10/15) were higher than that in nodular bronchiectasis (23.0%,14/61) (χ ²=10.649,P=0.001). Conclusion Nodular bronchiectasis type is the most common imaging features in NTM pulmonary disease. The upper lobe cavitary type is more common in male patients with emphysema and/or interstitial fibrosis. Nodular bronchiectatic type is frequently seen in female patients without underlying lung diseases.

Key words: Mycobacterium infections, atypical, Lung diseases, Tomography, X-ray computed, Diagnostic imaging