P Positron Emission Tomography (PET) is State-of-the-Art "in vivo" imaging of the biochemistry and functions in the body, allowing quantitative assessment of biological processes. PET allows for the measurement of function and metabolism in normal and diseased tissue.

PET Radiotracers which emit Positrons (rather than photons produced by conventional nuclear medicine tracers), are administered just prior to the PET Imaging Procedure.

These Positrons travel a short distance (1 to 2 mm) in the tissue before colliding with an electron. The Positron and the Electron annihilate each other and in the process emit two gamma rays of 511 keV each at 180 degrees to each other. The Gamma Rays are detected as pairs in coincidence by a series of specialized detectors arranged in a ring around the client.

Positron emitting isotopes exist for carbon, oxygen, nitrogen and fluorine among others which allows many naturally occurring substances (such as glucose, ammonia and water) to be labelled with radiotracers and by imaging the distribution of these tracers, regional blood flow and glucose metabolism can be imaged "in vivo".

FDG (18-Fluorodeoxyglucose), is a glucose analog which remains trapped in the tissue cells long enough for quality dynamic imaging to take place.