Is There Novel ¹⁸F-FDG Biodistribution in the Digital PET/CT Era? A Real-World Data Analysis

Background: This retrospective multicenter study investigated the biodistribution of fluorodeoxyglucose (¹⁸F-FDG) in the positron emission tomography (PET)/computed tomography (CT) in digital PET/CT (dPET) compared to analog PET/CT (aPET), focusing differences in physiological uptake in reference and small structures across various scanner models. Materials and Methods: One hundred thirty patients with similar preimaging conditions underwent both dPET and aPET imaging within 6 months. Visual evaluations and paired comparative analyses of semiquantitative parameters were performed for small and reference structures. Results: ¹⁸F-FDG uptake was higher in both reference and small structures for dPET compared to three different aPET scanners. The Siemens mCT20-4R (mCT20) demonstrated comparable results to dPET. Notably, mCT20 had higher standardized uptake value (SUV_max) for the conus medullaris (CM) (3.20 vs. 2.76). CM was most highly visible with dPET on visual evaluation by physicians. Conclusions: Digital PET/CT provides higher SUV values in both small and reference structures. This leads to improved visualization of ¹⁸F-FDG physiological biodistribution. Given the growing adoption of dPET technology, these advancements should be carefully considered in image interpretation and clinical research.