Hypermetabolic: Meaning in a Radiology Report

Also written as: hypermetabolism, increased metabolic activity, metabolically active, increased FDG uptake

Hypermetabolic means an area takes up more of the sugar-like tracer FDG than the tissue around it on a PET scan, so it looks brighter.

What it means

Most PET-CT scans use FDG, a tracer the body treats like sugar. Busy cells take up more sugar, for example cells that are dividing quickly, repairing tissue or fighting an infection. Hypermetabolic means a spot has taken up more FDG than the tissue around it, so it shows as a brighter area. Radiologists often give the amount as an SUV number.

When it matters

Many things besides cancer can be hypermetabolic, including infection, inflammation, recent surgery, healing fractures, busy muscles and brown fat (a heat-producing fat). The radiologist weighs the pattern, the size and shape on CT, and your history. Unclear spots may be checked on a later scan or sampled with a biopsy. During treatment, falling activity usually suggests the treatment is working.

Questions to ask your doctor

Could infection, inflammation or healing explain the uptake?
How does the activity compare with any earlier PET scan?
Does this spot need a biopsy or a follow-up scan?

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.