How Does a PET Scan Work?

A PET scan uses radioactive tracers to create 3D images of the body. The radiation from the tracers poses little danger to the patient since they quickly pass out of the body. The kind of tracer used will depend on what the doctor is looking for. Often when looking for cancer, doctors use FDG, a modified form of glucose. The isotope attached to the carrier molecule produces small particles called positrons, which interact with surrounding electrons. The resulting release of photons is detected by the PET scanner and translated into an image through computer processing.