Role of FDG PET/CT in bacteremia and fever of unknown origin: a pictorial overview of finding the culprit

18F fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) has established itself as a critical diagnostic tool in the evaluation of patients with bacteremia and fever of unknown origin (FUO), particularly following futile conventional investigations. These conditions are often challenging due to diverse underlying etiologies, including infections, inflammatory conditions and malignancies. PET/CT has the advantage of being a whole-body imaging technique with high sensitivity for detecting areas of increased metabolism often associated with infection or inflammation. In bacteremia, [18F]FDG PET/CT can help identify metastatic infections, endocarditis, or abscesses which may be clinically silent and missed on conventional imaging. In FUO, it helps to identify underlying etiologies, directing treatment and management strategies. This review aims to describe the role of PET/CT imaging in these diverse clinical scenarios. Perspectives in the field, including novel equipment and tracers, will be briefly discussed.