PET works by injecting a small amount of radioactive tracer into the body. This tracer is usually a biologically active molecule labeled with a positron-emitting isotope, such as Fluorodeoxyglucose (FDG). As these tracers accumulate in tissues, they emit positrons, which interact with electrons, resulting in the emission of gamma rays. These gamma rays are detected by the PET scanner, creating detailed images of the tissue's metabolic activity.
