What precaution should patients take prior to an FDG-PET scan?

Before an FDG-PET scan, it is important for patients to take several precautions to ensure the accuracy of the imaging results. Limiting physical activity is advised because strenuous exercise can increase glucose metabolism in the body, potentially leading to false positive results during the scan. Avoiding coffee is also crucial since caffeine can stimulate the central nervous system and alter glucose metabolism, which may impact the distribution of the FDG tracer. Additionally, controlling blood sugar levels is imperative, particularly for diabetic patients. Elevated blood sugar can cause an increased uptake of FDG in non-target tissues, which can obscure the detection of malignancies and affect the overall interpretation of the scan.

Taking all these precautions helps create optimal conditions for the FDG-PET scan, allowing for a more accurate assessment of metabolic activity within the tissues being examined. Thus, the correct answer encompasses all these necessary precautions to prepare patients effectively before the procedure.