Comparison of the chest computed tomography findings between patients with pulmonary tuberculosis and those with Mycobacterium avium complex lung disease

Background Since the computed tomography (CT) findings of nontuberculous mycobacterial lung disease are similar to those of pulmonary tuberculosis (PTB), we often have difficulty differentiating the two. In this study, we compared the differences in chest CT findings and their locations between cases of PTB and Mycobacterium avium complex lung disease (MACLD). Methods The subjects were 100 MACLD patients and 42 PTB patients treated at our hospital from May 2005 to August 2015. The CT findings were retrospectively evaluated. Results PTB more frequently showed lung shadows with calcification inside the lesion, calcification of the mediastinal/hilar lymph node, and pleural effusion on CT than MACLD, while extensive bronchiectasis and granular/large shadows connected to bronchiectasis were more frequently observed with MACLD than PTB. For cavitary lesions, the thinnest part of the cavity wall with MACLD was thinner than that with PTB. Granular shadows, large shadows, and bronchiectasis were typically distributed to the right upper lobe and left upper division in PTB cases vs. the right intermediate lobe and left lingula in MACLD. Conclusions Chest CT findings would therefore be useful for distinguishing PTB and MACLD when typical findings are observed.