What does PET scan avid mean?

In the context of a PET scan, "avid" refers to the degree to which a tissue or lesion absorbs the radioactive tracer used in the imaging process, typically a glucose analog like FDG (fluorodeoxyglucose). High avidity indicates increased metabolic activity, which is often associated with cancerous tissues, infections, or inflammation. Conversely, low avidity suggests reduced metabolic activity, potentially indicating benign conditions or necrotic tissue. Thus, "avid" helps radiologists assess the nature of abnormalities seen in the scan.