18F-FDG PET/CT in the evaluation of suspected infections following cardiothoracic surgical interventions

The incidence of cardiothoracic infections is steadily increasing, due to the expanding clinical indications and growing rates of cardiovascular device implantations and surgical interventions. ¹⁸F-FDG PET/CT has emerged as a highly valuable functional imaging modality, particularly when conventional imaging modalities are non-diagnostic, offering a distinct advantage as it may enable early diagnosis, potentially before structural changes become apparent, and allowing a whole-body assessment. This review offers a comprehensive overview of ¹⁸F-FDG PET/CT imaging in the setting of infections post cardiothoracic surgeries, exploring its diagnostic utility across various clinical scenarios, including prosthetic and native valve endocarditis, cardiac implantable electronic device (CIED) infections and left ventricular assist device (LVAD) infections, vascular graft infections, and post- sternotomy infections. Our aim in this review is to explore clinical scenarios in which ¹⁸F-FDG PET/CT should be considered and to clarify its integration into established diagnostic algorithms. Furthermore, we aim to characterize different uptake patterns that are highly suggestive of infection, correlating with anatomical findings, thereby providing practical guidance for image interpretation. Finally, this review seeks to address the limitations of ¹⁸F-FDG PET/CT and recognize potential pitfalls in interpretation of imaging. In all, emphasizing the need for standardization of imaging protocols and interpretation criteria.