FDGPET

FDGPET, commonly written as FDG-PET, is a molecular imaging modality that visualizes glucose metabolism in living tissues. It is often performed as part of a PET/CT study, which combines metabolic information from PET with anatomic detail from computed tomography to localize areas of abnormal tracer uptake.

The technique relies on 18F-labeled fluoro-deoxyglucose, a glucose analog. After intravenous injection, cells with high metabolic activity take up more FDG and retain it longer. PET then detects the emitted positrons to create a three-dimensional map of tracer distribution, which is quantified with standardized uptake values (SUVs). The uptake pattern reflects tissue metabolism rather than mere anatomy.

FDG-PET has broad clinical use. In oncology, it is used for cancer staging and restaging, detecting metastases, guiding biopsy, and assessing response to therapy. In neurology, FDG-PET aids in evaluating suspected dementia syndromes and localizing epileptogenic foci in some patients. In cardiology, it can assess myocardial viability to guide revascularization decisions.

Standard procedure requires fasting and avoidance of strenuous activity before tracer administration. Imaging typically occurs about an hour after injection. PET is often combined with CT (PET/CT) to improve anatomical localization; PET/MRI is also used in some centers.

Interpretation considers the pattern and intensity of uptake, against patient history and complementary tests. Limitations include false positives from inflammation or infection, false negatives in certain tumors, radiation exposure, cost, and limited specificity. Safety and radiation-protection principles guide use, with careful consideration in pregnancy and lactation.