PET (Positron Emission Tomography) is a non-invasive test that accurately images metabolic information in the body.  PET focuses on Oncology, Cardiology, and Neurology.  Each patient is given an injection of FDG (flurodeoxyglucose) which is similar to a naturally occurring sugar with the addition of a radioactive fluorine atom.  There is no danger to the patient from this injection.  The scanner then utilizes the radiation coming from the patient to take images before the FDG is broken down and released by the body.