The role of nuclear medicine in abdominopelvic infections

Abdominopelvic infections remain a major diagnostic challenge despite advances in anatomical imaging. Clinical presentation is frequently nonspecific, biomarkers lack accuracy, and cross-sectional techniques such as computed tomography often fail to identify early, postoperative, or low-grade infections precisely when timely intervention is most critical. In this context, functional imaging has emerged not merely as a complementary modality, but as a decision-shaping tool capable of resolving diagnostic uncertainty. Nuclear medicine techniques provide unique pathophysiological insights that extend beyond structural assessment. ¹⁸F-FDG PET/CT offers high sensitivity for detecting metabolically active disease and is particularly valuable in identifying occult infection and guiding whole-body evaluation. However, its lack of specificity limits its ability to distinguish infection from sterile inflammation, especially in the postoperative abdomen. In contrast, radiolabeled leukocyte scintigraphy retains a critical role due to its pathogen-oriented specificity and resistance to physiological background activity in the gastrointestinal and urinary systems. Rather than competing modalities, ¹⁸F-FDG PET/CT and leukocyte imaging address complementary clinical questions: the former is optimized for detecting disease activity, whereas the latter provides confirmation of true infection. Their appropriate use should therefore be guided by the underlying diagnostic dilemma rather than by availability alone. This review examines the role of nuclear medicine in the management of abdominopelvic infections from a clinical decision-making perspective, highlighting scenarios in which functional imaging alters patient management, discussing key pitfalls, and outlining emerging approaches aimed at achieving pathogen-specific imaging.