The quantitative carbohydrate ingestion ratio for extensive skeletal muscle uptake in 18F-FDG PET/computed tomography

Extensive skeletal muscle accumulation (ESMA) of F-FDG adversely affects the visual interpretation of F-FDG PET/computed tomography (CT) images. We mainly investigated factors related to ESMA that are based on food compositions.

From January 2018 to June 2018, a total of 5554 patients underwent F-FDG PET/CT imaging with at least a 4-hour fast. Among them, 49 patients who exhibiting ESMA and 50 sex-matched and age-matched patients without ESMA were included in the study. The following factors were analysed: BMI, plasma glucose, gastric residue, the total energy of food the patient had before F-FDG injection and the percentages of the food ingredients. Multivariate analysis was performed to evaluate related risk factors between two groups.

In brief, 49 cases and 50 controls were identified. The BMI, gross energy, gross energy of protein, gross energy of carbohydrate and proportion of protein of case group were not significantly different from that of the controls (P ≥ 0.05). The plasma glucose was significantly higher in the case group than in the control group (P = 0.002). The positivity of gastric food residue would more easily demonstrate ESMA than those without gastric food residue (P < 0.0001). The fasting time before scan, gross energy of fat, proportion of fat and proportion of carbohydrate in case group were significantly different with control group. After multivariate analysis, fasting time, gastric food residue and proportion of carbohydrate were investigated as independent risk factors.

To avoid ESMA, patients should take a lower proportion of carbohydrate before receiving an F-FDG administration.