Positron Emission Technology scans, commonly called PET scans, detect the metabolic activity of tissues to determine how bodily structures behave. PET scans are often used to detect abnormal muscle tissue and tumors, brain activity and blood flow, as well as the effects of cancer therapy.

Before the exam, a radioactive substance is administered to the patient, usually via injection, allowing the PET scanner to focus on a specific area of the body. During the scan, patients pass through a large ring containing multiple rings that record the release of energy from the radioactive substance in your body. Various colors and degrees of brightness displayed in a PET image represent levels of organ and tissue activity.

Sometimes, PET scans are performed in concert with CT scans. The images resulting from these hybrid scans display metabolic activity in relation to the body’s anatomy.