Abdominal computed tomographic findings of Mycobacterium tuberculosis and Mycobacterium avium intracellulare infection in HIV seropositive patients.

OBJECTIVE: To compare the computed tomographic (CT) findings of abdominal Mycobacterium tuberculosis (MTB) infection and Mycobacterium avium intracellulare (MAI) infection in patients with human immunodeficiency virus (HIV) infection. METHODS: A retrospective review of the CT findings of 30 patients with HIV and proven MTB (n = 9) or MAI (n = 21) infection was conducted. Images were reviewed by a radiologist blinded to the diagnosis, and the radiologic findings involving the abdominal viscera, peritoneum and lymph nodes were compared. RESULTS: The following were more frequent in patients with MAI infection: hepatomegaly (MAI 71% v. MTB 44%, p < 0.05), uniform attenuation of lymph nodes (MAI 90% v. MTB 55%, p < 0.05) and clustered pattern of lymph nodes (MAI 57% v. MTB 22%, p < 0.05). In patients with MTB infection, lymph nodes with low attenuation centrally were more common (MAI 10% v. MTB 44%, p < 0.05), and mesenteric lymph nodes were significantly larger (MAI mean = 20 mm v. MTB mean = 40 mm, p < 0.05). CONCLUSION: Although nonspecific, CT may be useful in the early diagnosis of MTB and MAI infection, allowing for presumptive treatment before microbiologic confirmation.