Positron Emission Tomography (PET Scan)

What Is It?

Published: September, 2020

A positron emission tomography, or PET, scan is an imaging technique that uses radioactive tracers attached to sugar molecules. The scan can detect changes in the body's metabolism and chemical activities. A PET scan is often done in conjunction with a CT scan. The combination provides a color-coded image of the body's structure and function.

During a PET scan, the sugar molecules with the attached radioactive tracers are injected into a vein. Once the substance enters the body, it travels through the bloodstream to the body's organs. Areas in the body that have a higher rate of metabolism use more sugar. So these areas pick up the sugar molecules more readily than normal.

To continue reading this article, you must log in.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise

New subscriptions to Harvard Health Online are temporarily unavailable. Click the button below to learn about our other subscription offers.

Learn More »