CT and pathologic correlation of acute miliary pulmonary tuberculosis

Objective To elucidate the CT characteristics and pathology of acute miliary pulmonary tuberculosis (AMPT). Methods The CT features of AMPT in 25 cases were analyzed retrospectively, and the CT features in HIV-seronegative and HIV-seropositive patients were compared by 2-sided exact propability Chi-square test. Two lung specimens were inflated and fixed by Heitzman's method. HRCT scans, gross specimen section (80-150 μm) and histologic section (5 μm) were performed on dry lung specimens and CT-pathologic correlation was conducted. The distribution of micronodules in the secondary lobule on HRCT and pathology in one specimen was evaluated by Chi-square test. Results Twenty five patients with AMPT were included in this study, including 11 HIV-seropositive patients and 14 HIV-seronegative patients. HRCT showed diffuse micronodules randomly distributed throughout both lungs in 25 patients, and ground-glass opacity (17 patients)was the predominant complicated finding. Coalescence of nodules and consolidation in HIV-seropositive patients (5 and 6 patients) were markedly higher than that in HIV-seronegative patients (none). In lung specimens, most nodules located in the lung parenchyma between the central bronchovascular bundle and the perilobular structures (792 and 560 nodules), which located in the interlobular septum pathologically. The distribution of micronodules in the secondary lobule showed on HRCT (1060 nodules)and pathology(864 nodules) was not significantly difference(x2=2.814,P＞0.05). HRCT showed ground-glass opacities when ARDS occured, which were pulmonary edema,inflammation and hyaline membrane on alveolar wall pathologically. Conclusions The HRCT characteristic of nodule distribution in AMPT is random. ARDS should be suspected when diffuse ground-glass opacities appear on HRCT. Key words: Tuberculosis, pulmonary;  Tuberculosis, miliary;  Tomography, X-ray computed;  Diagnosis