18F-FDG PET/CT Imaging of Infection and Inflammation

Introduction: To review and characterize the role of 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in sterile and septic inflammatory processes.

Methods: Since the initial clinical utilization of the glucose analogue, ¹⁸F-FDG, clinicians have understood the potentiality of this radiopharmaceutical for the evaluation of an important and diverse group of pathological conditions, characterized by infection and aseptic inflammation. Given the high energy consumption of white blood cells activated by either a pathogen or as part of a systemic inflammatory disease and therefore avidly taking up ¹⁸F-FDG, it is not surprising that a rapidly expanding body of evidence now supports the clinical utility of ¹⁸F-FDG PET/CT in suspected infection and inflammation. ¹⁸F-FDG PET/CT can identify the source of infection or inflammation in a timely manner prior to the appearance of morphological changes on conventional anatomical imaging modalities, map the disease extent, characterize sites for tissue sampling, and evaluate therapy response. This yet evolving hybrid imaging technique offers distinct advantages over traditional radionuclide imaging techniques, such as higher spatial resolution, shorter duration of imaging, integration of functional and anatomical data, and the non-invasive nature of the acquisition.

Results: We will discuss the utility of ¹⁸F-FDG in inflammatory and infectious diseases such as osteomyelitis, cardiac implantable electronic device infection, infective endocarditis, prosthetic valve endocarditis, vascular graft infection, prosthetic joint infection, fever of unknown origin (FUO), COVID-19 infection, tuberculosis, sarcoidosis, human immunodeficiency virus (HIV)-related disease and autoimmune conditions such as vasculitis, inflammatory bowel diseases, IgG4-related diseases and rheumatoid arthritis.

Conclusions: This educational exhibit will highlight the utility and limitations of ¹⁸F-FDG PET/CT for the diagnosis and assessment of treatment in infections and inflammatory conditions.