PET is an advanced medical procedure that takes detailed images of an organ or system in the body with the use of a radioactive substance called a 'tracer'. The scans are commonly used to evaluate and diagnose cancers, neurological (brain) disorders, and cardiovascular (heart) diseases.
During a PET scan, a radioactive tracer is injected into the blood and images of the body are recorded using a PET scanner. The scanner detects the emissions of the radioactive tracer in the body and a computer then creates multi-dimensional images of the part of the body being examined. The radiotracers usually gather in diseased tissues more than in healthy tissues, thus highlighting them for the scanner to record. Most PET scanners are combined with computed tomography (CT) scanners. This further allows the structural information provided by CT images to be combined with the PET’s functional information.