ARRT Nuclear Medicine Practice Test 2026 – Complete Prep Guide

A contraindication for performing a PET study using fluorodeoxyglucose (FDG) relates to the patient's blood glucose level. Specifically, a blood glucose level of 200 mg/dL or higher can lead to suboptimal imaging results. This is because elevated glucose levels can cause competition with FDG, which is a glucose analog. As a result, high blood glucose can lead to decreased uptake of FDG in tissues, potentially masking abnormalities, especially in cancer detection, which is one of the primary uses of PET scans.

To obtain accurate and reliable PET imaging, it is critical that the patient's blood glucose level is within an acceptable range before administering FDG. Typically, a fasting blood glucose level below 200 mg/dL is recommended to ensure optimal visualization of metabolic activity.

Other factors, such as body temperature, age, and recent use of aspirin, while they may impact a patient's overall health or affect diagnostic clarity, do not directly compete with FDG uptake in the same way that blood glucose does. Therefore, monitoring and managing blood glucose levels is crucial in the context of preparing for a PET study using FDG.