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Effect of oral hypotonic water and isotonic saline on physiological intestinal 18F-FDG uptake in PET/CT imaging

Weng S, Li Y, Liu X, Wang Q

Journal of applied clinical medical physics, 2026

185 participants

Abstract

Purpose: Hydration of patients before the PET/CT examination may lead to non-specific FDG accumulation in the intestine. This study aims to explore the influence of isotonic saline and hypotonic water on physiologic intestinal 18F-FDG uptake in PET/CT imaging.

Methods: 185 patients were included, 82 patients were randomized to receive oral administration of isotonic saline and 103 patients received oral administration of hypotonic water before examination. About 32 patients in the isotonic group and 19 patients in hypotonic group underwent repeated PET/CT with pre-administration of hypotonic water, and the intra-individual comparative analysis was performed for the first and second examinations. Segmental uptake patterns were documented and volumetric regions of interest were delineated. The SUVmax of intestinal segment and the SUVmean of liver were recorded.

Results: No significant differences existed in baseline characteristics between the two groups. The isotonic group demonstrated lower physiological uptake incidence and target-to-background ratio (TBR) in all segments except jejunum and ascending colon (p < 0.05). Physiological uptake incidence in jejunum showed no intergroup difference, whereas the TBR of isotonic group showed lower tendency. Notably, the isotonic group exhibited higher physiological uptake incidence (p < 0.001) in the ascending colon, though no significant difference existed in TBR between two groups. These results were similar in intra-individual…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 185 participants or records.

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