Mycobacterium tuberculosis Versus Nontuberculous Mycobacterial Infection of the Lung in AIDS Patients: CT and HRCT Patterns

Abstract

The aim of this study was to determine discriminating CT and HRCT features between mycobacterial pulmonary tuberculosis and nontuberculous mycobacterial (NTMB) pulmonary infections in patients with AIDS. CT and HRCT scans of 52 AIDS patients with culture-proven mycobacterial infection [29 with Mycobacterium tuberculosis (MTB) and 23 with NTMB] without concomitant pulmonary infection were reviewed by two observers. Nodular opacities, mainly centrilobular in distribution, were the most common finding, seen in 21 (72%) and 15 (65%) of patients with MTB and NTMB, respectively. A lower lobe predominance of centrilobular nodules was seen more commonly in NTMB (p < 0.03). Ground-glass attenuation was seen in 5 (17%) and 11 (48%) of patients with MTB and NTMB, respectively (p = 0.03). Ground-glass opacities and bronchial wall thickening affected a larger number of lobes in NTMB (p < 0.01), while centrilobular nodules involved more lobes in MTB (p < 0.01). A higher prevalence of unilateral lung involvement was seen in MTB (12 patients, 44%) than NTMB (1 patient, 5%) (p < 0.01). Enlarged lymph nodes were more frequent in patients with MTB than in those with NTMB (22, 76% vs. 10, 43%, respectively) (p < 0.02). NTMB infection and pulmonary tuberculosis display different CT and HRCT patterns in AIDS patients, but there is considerable overlap in CT findings.