RESUMO
OBJECTIVE: This study aims to describe patterns of pulmonary tuberculosis (TB) on FDG-PET/CT. METHODS: All patients with a diagnosis of TB and who underwent FDG-PET/CT between January 2009 and June 2010 were included. Clinical, biological and imaging data were reviewed. TB was proven either on bacteriological or histopathological studies (n=13) or on a clinical and imaging basis (n=3). RESULTS: Sixteen patients (11 men; median age 56, range 22-84 years) were included. Two distinct patterns were identified. In the lung pattern (9/16), patients had predominantly pulmonary symptoms (6/9 patients, 67%) with a parenchymal involvement: uptakes on lung consolidation ± cavitation surrounded by micronodules. Mediastino-hilar lymph nodes were slightly enlarged (15 mm, 10-27) with moderate uptake (3.9, 2.5-13.4). In the lymphatic pattern (7/16), patients had predominantly systemic symptoms (5/7 cases, 71%) and all had extra-thoracic involvement. Mediastino-hilar lymph nodes were more enlarged (30 mm, 18-35, p=0.03) and with higher uptake (6.8, 5.7-16.8, p=0.034) than in the lung pattern. CONCLUSION: We identified two distinct patterns of pulmonary TB on FDG-PET/CT. The lung pattern related to a restricted and slight hypermetabolic infection and the lymphatic pattern related to a systemic and intense infection. Combined interpretation of PET and CT findings improves the specificity of images, especially for the lung pattern.
