A computer-based medical imaging technique for examining blood flow in the brain and in other body tissues making use of slightly radioactive tracer that emit positrons. The tracer which is linked to sugar molecules is injected into the subject’s blood and then it’s concentration is measured using the emitted positrons.As cells need sugar to function; active cells can be located by visualizing places where greater amounts of radioactive tracers are found.
Positron emission tomography (PET) is used for measuring brain function in living subjects. It allows visualizing the active areas (where brain cells absorb sugar) and provides a picture of the brain’s activity rather than its structure.
PET is also used to identify cancerous tissues. As cancerous cells absorb large amounts of sugar, cancer tumours can be detected by looking at the places where the radioactive sugar collects in large amounts.