Positron Emission Tomography (PET)

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Test Overview

Positron emission tomography (PET) is a test that uses a special type of camera and a tracer (radioactive chemical) to look at organs in the body.

During the test, the tracer liquid is put into a vein (intravenous, or IV) in your arm. The tracer moves through your body, where much of it collects in the specific organ or tissue. The tracer gives off tiny positively charged particles (positrons). The camera records the positrons and turns the recording into pictures on a computer.

PET scan pictures do not show as much detail as computed tomography (CT) scans or magnetic resonance imaging (MRI) because the pictures show only the location of the tracer. The PET picture may be matched with those from a CT scan to get more detailed information about where the tracer is located.

A PET scan is often used to find cancer, to check blood flow, or to see how organs are working.

See pictures of a PET scanner and PET scans of the brain .

Last updated:	September 11, 2007
Author:	Maria G. Essig, MS, ELS
Reviewed By:	Adam Husney, MD - Family Medicine, Paul D. Traughber, MD - Radiology
Editors:	Susan Van Houten, RN, BSN, MBA, Tracy Landauer