FDG-avid: Meaning in a Radiology Report

FDG-avid

Also written as: FDG avid, FDG uptake, FDG-positive, FDG avidity

FDG-avid means a spot takes up FDG, the sugar-like tracer used in most PET scans, so it lights up on the images.

Seen on: PET and nuclear medicine

How it reads in a report

The 8 mm nodule in the left upper lobe is not FDG-avid, although PET has limited sensitivity at this size.

What it means

FDG is a sugar-like substance with a small radioactive label. Cells that use a lot of energy take it up, and the PET scan shows where it builds up. A spot described as FDG-avid holds more tracer than the tissue around it. Reports may add mildly, moderately or intensely, often with an SUV number. Not FDG-avid means the spot took up no more than its surroundings.

When it matters

FDG-avid is not specific, meaning it does not point to one cause. Cancer, infection, inflammation and healing tissue can all take up FDG. A spot that is not FDG-avid is often reassuring, but not a guarantee. Some cancers take up little FDG, including certain slow-growing lymphomas, many prostate cancers and some lung cancers. Very small spots may not show at all. So the result is read with the CT images, your history and sometimes a biopsy.

Questions to ask your doctor

How strongly FDG-avid is it, and what was the SUV?
Could infection or inflammation explain the uptake?
Is FDG a good tracer for the kind of condition being checked?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.