The PET Scan: Detecting Diseases Through Radiation Medicine

Positron emission tomography, better known as a PET scan, is an imaging test used for diagnostics. Together with a tracer, which is a radioactive substance that works as a dye, a PET scan is able to detect certain diseases. Your physician will choose a tracer based on the organ that is to be examined.

The tracer is a short-life radioisotope with sugar. This tracer may be inhaled or even swallowed prior to the scan, or administered intravenously (via an IV) during the scan. After the films are taken, a radiologist will compare these films with a CT (computed tomography) or an MRI (magnetic resonance imaging) to better identify what is happening around the organ or body tissues.

The most common substance used for tracing is FDG, a radioactive form of glucose sugar. This small dose of radiation is useful as it has a short half-life. This tracer is absorbed by the body of the patient in about 2 hours. They leave the body via one’s urine. There are no side effects from the tracer; however, if a patient is pregnant or is nursing, they should report it to the physician.

The scan takes around an hour to carry out but the entire procedure will take about 2 hours as there needs to be a half hour from the time the tracer is administered to the time the scan can commence. The patient will lie on a cushioned examination table and be asked to not move when the scanning is taking place. Patients should not eat or drink up to six hours before the test and wear comfortable clothing. All jewelry should be removed.

A PET scan is very useful because the tracer spots are bright and it helps the physician to determine the shape and size of anything abnormal around the affected tissue or organ. The emitted positrons help detect diseases such as brain disorders, cancers, or heart disease.