Role of [18F] FDG PET/CT in Critically Ill Patients: A Comprehensive Review for Clinical Practice.

Critically ill patients may experience fever, shock, or organ malfunction that is difficult to diagnose with traditional organ-targeted imaging and culture-based methods. This review summarizes the biological rationale, intensive care unit-specific preparation and transport logistics, clinical indications, diagnostic performance, and false-positive and false-negative pitfalls of whole-body 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) as a metabolic imaging tool for localizing occult infectious or inflammatory foci in this population. Its clinical influence is demonstrated by representative cases. FDG PET/CT should be utilized as a targeted, clinically integrated adjunct rather than a first-line or stand-alone diagnostic.