Preparation methods prior to PET/CT scanning that decrease uptake of 18F-FDG by myocardium, brown adipose tissue, and skeletal muscle.

Background: The hypermetabolic environment of the myocardium, brown adipose tissue (BAT), and muscle will have an effect on the diagnostic accuracy of 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET)/computed tomography (CT). A low carbohydrate, high fat, and protein-permitted diet before PET/CT scanning can reduce the degree of 18F-FDG uptake by the myocardium, brown adipose tissue, and skeletal muscle.

Objective: To determine the effect of a low carbohydrate, high fat and protein-permitted diet on 18F-FDG uptake by myocardium, BAT, and muscle during PET/CT.

Methods: A total of 126 patients who adhered to two meals before PET/CT scanning (that were prepared using a low carbohydrate, high fat, and protein-permitted diet), i.e. the diet group, were compared with 126 patients who fasted for at least 12 h prior to scanning (i.e. the fasting group). The degree of 18F-FDG uptake within the myocardium, BAT, and muscle were stratified into four grades (range, 0-3) with 0 for negligible uptake, and 3 for intense uptake. Correlations between the diet and fasting groups with respect to degree of 18F-FDG uptake within the myocardium, BAT, and muscle were analyzed.

Results: The degree of 18F-FDG uptake within the myocardium, BAT, and muscle in the diet group was significantly lower compared with the 18F-FDG uptake within myocardium, BAT, and muscle in the fasting group (P < 0.001, P = 0.001, P < 0.001).

Conclusions: A low carbohydrate/high fat diet before 18F-FDG injection can suppress uptake of 18F-FDG within the myocardium, BAT, and skeletal muscle.