What is the maximum blood glucose level permissible for a PET/CT scan?

In the context of a PET/CT scan, the maximum blood glucose level that is generally considered permissible for optimal imaging is 150 mg/dL. A blood glucose level above this can lead to decreased image quality and can potentially affect the distribution of the radiotracer, fluorodeoxyglucose (FDG), that is used during the scan. Elevated glucose levels can cause competitive inhibition with FDG uptake in tissues, primarily in tumors that rely on glycolysis for energy.

When blood glucose levels are maintained at or below this threshold, it helps ensure that the PET/CT scan delivers accurate diagnostic information, as the tissues of interest will uptake the FDG more efficiently, leading to clearer and more interpretable results. In clinical practice, managing a patient's blood glucose is particularly important for ensuring the effectiveness of the imaging study and providing reliable diagnostic outcomes.