Q: 64 year old female admitted in ICU is going for PET scan. Service requested you to keep patient NPO four hours prior to procedure and low carbohydrate diet 24 hours prior to procedure if feasible?


Answer: Hyperglycemia can interfere with PET scan. High serum glucose level competes with the fluorodeoxyglucose (FDG) for the same cell surface receptor and decreases intracellular FDG.


References:

Torizuka T, Clavo AC, Wahl RL. Effect of hyperglycemia on in vitro tumor uptake of tritiated FDG, thymidine, L-methionine and L-leucine. J Nucl Med 1997; 38:382.