Definition

     An imaging technique that shows metabolic activity in the brain.

Alternative Names

      PET Scan or PET Imaging

How the test is performed

     PET measures how intensely different parts of the brain use up glucose, oxygen, or other substances.

     Positron emission tomography is a diagnostic examination that involves acquiring physiologic images based on the detection of radiation from the emission of positrons. Positrons are tiny particles emitted from a radioactive substance administered to the patient. The subsequent images of the human body developed with this technique are used to evaluate a variety of diseases.

How to prepare for the test

     The test will take approximately 90 minutes.

     You will need to fast for at least 6 hours before the PET scan. You are however, encouraged to drink several glasses of water before the test.

     Wear comfortable clothing.

     Same amount of radiation as a CT head scan will be emitted.

How the test will feel

     This test itself causes no discomfort.

     A radioactive substance will be given intravenously.

     You will lie in a cushioned examination table and will be asked to rest quietly and avoid significant movement or talking, which may alter the localization of the administered substance.

Why the test is performed

      PET scans of the brain are used to evaluate patients who have seizure disorders that are not responsive to medical therapy and are therefore candidates for surgery. PET scan is one modality used to indicate the origin of a seizure.