How PET Works
The body relies on glucose for energy. Before a PET scan, a patient is injected with a harmless radioactive glucose/water solution, called a "tracer." Once the tracer is inside the body, the patient is positioned into the PET scanner.As the body processes the tracer compound, positrons begin to collide with electrons, causing gamma rays to be emitted. These gamma rays are detected and measured by the PET scanner/ A computer uses the measurements to create pictures of the various organs at work within the body. The images allow physicians to differentiate healthy tissue from unhealthy tissue.
The PET scanner itself does not produce any radiation. It merely picks up signals from the tracers already in your body.