FDG PET/CT in vascular graft infection: a pictorial review.

Vascular graft infections (VGI) are rare but severe complications following vascular surgery, with significant morbidity and mortality. Diagnosing VGI requires a multidisciplinary approach combining clinical, laboratory, and imaging findings. While CTA remains the first-line imaging modality, its limitations in detecting chronic or low-grade infections highlight the value of advanced nuclear medicine techniques, particularly [¹⁸F]FDG PET/CT. In this review, we discuss the role of [¹⁸F]FDG PET/CT in diagnosing VGI, emphasizing its high sensitivity and negative predictive value, which are critical for ruling out infection. Nevertheless, there are currently no universally accepted criteria for analyzing PET/CT findings in VGI, which poses challenges for consistent interpretation and clinical decision-making. This review aims to provide a comprehensive understanding of FDG PET/CT imaging in the context of VGI by exploring visual grading scales, uptake patterns, and semi-quantitative parameters while highlighting potential pitfalls such as post-surgical inflammation and false-positive results due to graft materials or surgical adhesives. Through a series of illustrative cases, we outline characteristic imaging patterns of infected and non-infected grafts, offering practical guidance for accurate interpretation. Additionally, we discuss the evolving role of FDG PET/CT in assessing treatment response and guiding follow-up in VGI management. This pictorial review seeks to enhance diagnostic accuracy and bridge the gap in standardized PET/CT interpretation criteria, ultimately contributing to improved patient care.