positron emission tomography

n. (PET) A method of creating images of the insides of bodies including the brain by means of computer analysis of the absorption of positron emitting radioactive chemicals ingested by or injected into subjects and then differentially absorbed by different tissues. This procedure leads to interpretable spatial patterns of data received by arrays of positron receptors. This technique allows analysis of functioning of different tissues during different activities such as the absorption of the radioactive sugar, fluorine-18 labeled 2-deoxyglucose, which is taken up by brain cells in proportion to their activity level.