Advances in imaging of tuberculosis: the role of 18 F-FDG PET and PET/CT

Abstract

PURPOSE OF REVIEW : To review the main applications, advantages and limitations of 18F-FDG PET and PET/computed tomography (CT), and some other tracers in imaging of tuberculosis (TB). RECENT FINDINGS : In pulmonary TB, granulomas typically demonstrate increased 18F-FDG uptake, and areas of active TB can be differentiated from old or inactive disease by dual time point imaging. However, standardized uptake value measurements are high in both TB and malignant lesions, with significant overlap that limits their usefulness. In extrapulmonary TB, 18F-FDG PET detects more tuberculous lesions than CT, is of value in assessing response to tuberculostatic treatment, and helps in diagnosing spinal infection and identifying TB-related spondylitis; however, again, differentiation of malignant versus TB lymph node involvement is problematic. 18F-FDG PET can also be considered a marker of disease status in patients with HIV and TB co-infection. Overall, evaluation of treatment response is potentially the most important clinical application of 18F-FDG PET in TB, owing to its ability to distinguish active from inactive disease. SUMMARY : 18F-FDG PET and PET/CT may assist early diagnosis and facilitate differentiation between malignancies and TB, identification of extrapulmonary TB, staging of TB, and assessment of treatment response.