How to Prepare
- Before a PET scan, tell your doctor if you are or might be pregnant.
- You may be asked to sign a consent form authorizing this procedure. Use this opportunity to ask any questions you may have about the need for this test or how it will be done.
- Depending on the part of the body being examined, you may be asked to undress and put on a hospital gown. Otherwise, you should wear loose-fitting, comfortable clothing, with no jewelry or other metallic objects.
- Because you will have to lie still for an extended period of time, do not drink a lot of fluid before the test. For your own comfort, you should empty your bladder before the test begins.
Rarely, you may be asked to:
- Not smoke or drink any beverages containing alcohol or caffeine for 24 hours before the test.
- Stop taking any medications for 24 hours before the test. If you take insulin to control diabetes, you should take your insulin before the test.
- Avoid eating or drinking for 8 to 12 hours before the test.
If you are having a PET scan of your abdomen, you may need to take a laxative the evening before the test (and possibly have an enema the morning of the test). However, this is rare.
How It Feels
You may feel nothing at all from the needle puncture when the tracer is injected, or you may feel a brief sting or pinch as the needle goes through the skin. The scanning procedure itself is painless.
You may feel claustrophobic when you are placed inside the scanner.
You may be uncomfortable lying still for an extended period of time on the table during the scan.