What to expect


What is a PET/CT Scan?

A positron emission tomography and computed tomography (PET-CT) scan is an imaging test used to learn more about the cancer’s stage and where it has spread to. It is also used to:

  • Find the right place to do a biopsy

  • Find out how well treatment is working or has worked

  • Plan radiation therapy



Preparing for your PET/CT Scan


You will need to take specific steps, or preparations, before the scan. These may be different, depending on the specific scan you receive, but preparations often include:


  • Avoid exercising 24 hours before the scan.

  • Follow a special diet for 24 hours before the scan.

  • Don’t drink or eat anything, except water, for 6 hours before the scan.

  • Or there could be no preparation 


Before the PET-CT Scan 

Wear comfortable clothing for the scan. You may need to remove anything that contains metal, such as eyeglasses, dentures, or hearing aids, during the test.

 An intravenous (IV) line will be placed into a vein. You will then receive an injection of a radioactive substance called a radiotracer or tracer. It enters your body through the IV line. The substance takes 60 to 90 minutes to travel all over the body. During that time, you’ll need to remain still and stay relaxed.


During the PET-CT Scan

The scanning device is a large machine with a donut-shaped hole in the middle. When the exam starts, the table slides quickly through the hole. This first pass shows the technologist if you’re in the right body position to get the needed images. Then, the table slides slowly back and forth. You will need to stay still. The technologist might raise, or lower the table during the scan. The scan can take from 15 minutes to 45 minutes. 

During the exam, you’ll need to remain still to prevent motion during the scan, technologists will be in a nearby room monitoring your test through a window.


After the PET-CT Scan

After the PET-CT scan, you can return to your usual diet and activities. This includes driving. Drink lots of water. It helps wash any leftover radioactive substance and dye out of your body. Stay away from children and pregnant women for 24 hours following the time of injection.