Positron emission tomography (PET)

Positron emission tomography (PET) is a type of nuclear imaging test used to examine the chemical activity in parts of your body. A PET scan uses a special camera and a radioactive chemical, known as a tracer, to allow doctors to view organs in your body. The chemical is a special substance that will collect in cells that are using an excess of energy.

A PET scan can help your physician diagnose or assess conditions such as:

PET Scan: What to Expect

A PET scan can take between 1 to 3 hours. A radiologist or nuclear medicine specialist and a technologist administer the scan.

You will be asked to lie on a table. Before the test begins you will be given the tracer by IV. It can take up to 60 minutes for the chemical to move throughout your body.

During the scan, the PET scanner will move around your body as you lie still. The scanner makes buzzing and clicking sounds, but the procedure is completely painless.

The tracer used in the test contains small amounts of radiation. However, the risk of side effects is low.

After the test is complete, the technologist will provide images from the scan to your doctor.

PET Scan: How to Prepare

Before your PET scan, tell your doctor if you:

  • Are pregnant or breastfeeding
  • Have any allergies
  • Are taking any medications or supplements
  • Have diabetes or another medical condition
  • Are uncomfortable in enclosed spaces

To prepare for your test:

  • Avoid drinking caffeine or alcohol or smoking cigarettes for 24 hours prior to your appointment.
  • Do not eat or drink for at least 6 hours prior to your appointment.