[Evaluation of mycobacterial infections using 18F-fluorodeoxyglucose-positron emission tomography: results of nine cases].

18F-fluorodeoxyglucose-positron emission tomography (FDG-PET/CT) is a useful technique for distinguishing malignant and benign lesions, although the occurrence of false-positive results in cases involving benign lesions is possible. We evaluated nine patients with mycobacterial infections who underwent FDG-PET/CT from April 2008 to July 2010. FDG-PET/CT was performed 1-2h (during the early and late phases) after administration of FDG at a dose of 185 MBq/individual after fasting for at least 5h. Out of the nine patients, four were diagnosed with pulmonary nonmycobacterium tuberculosis, two with pulmonary tuberculosis, two with tuberculous lymphadenopathy, and one with pleural tuberculoma. All patients had a maximum standardized uptake value (SUV(max)) of > 2.5, and the SUV(max) increased from the early to the late phase. One lesion that occurred due to tuberculous pleurisy after treatment demonstrated high FDG uptake, similar to the other cases. It is difficult to distinguish mycobacterial infections from malignant diseases using FGD-PET alone; hence, the use of high-resolution CT and bacteriological tests is required for diagnosis and distinction.