Updates on tuberculosis imaging

Tuberculosis (TB) remains a leading infectious cause of morbidity and mortality worldwide, and major diagnostic and therapeutic challenges persist despite advances in microbiologic and molecular testing. Over the past decade, molecular imaging, especially with FDG PET/CT, has transformed our understanding of TB pathogenesis, the spectrum of early and subclinical disease, mechanisms of dissemination, and treatment response. This review synthesizes key recent developments in TB imaging, focusing on studies published since prior Seminars in Nuclear Medicine reviews. New non-human primate and human PET/CT data provide unprecedented insight into the spatial and temporal evolution of granulomas, demonstrating highly localized microanatomic seeding, bronchogenic spread pathways, and heterogeneous lesion biology that strongly influence treatment outcomes. Imaging studies in asymptomatic individuals reveal that metabolically active subclinical TB is common and strongly predictive of future progression, redefining the spectrum of latent infection. In treatment monitoring, FDG PET/CT consistently outperforms conventional microbiologic biomarkers, correlating with lesion-level sterilization and identifying patients at risk for relapse, particularly when persistent metabolic activity remains at the end of therapy. The introduction of emerging tracers, such as integrin-targeted probes, offers complementary characterization of granuloma angiogenesis, immune microenvironments, and host-pathogen dynamics beyond glucose metabolism. Future priorities include the development of TB-specific radiotracers, the integration of PET with advanced computational modeling and AI-based quantification, and the translation of imaging biomarkers into individualized treatment strategies and drug-development pipelines. Collectively, these advances position molecular imaging as a central tool in elucidating TB biology and accelerating progress toward improved diagnostic, therapeutic, and prevention strategies.