PET Scan

PET scan (positron emission tomography) is a test that creates pictures of the inside of your body. For the test, a small amount of radioactive material is injected into a vein. A special scanner then takes pictures of your body.

The pictures created during a PET scan can be used to study diseases, like cancer. The colors and brightness on the pictures show different levels of organ and tissue function. For example, cancer tissue appears brighter than normal tissue on a PET scan image.

Tell a health care provider about:

• Any allergies you have.
• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
• Any blood disorders you have.
• Any surgeries you have had.
• Any medical conditions you have.
• If you are afraid of cramped spaces (claustrophobic). If claustrophobia is a problem, it usually can be relieved with a medicine to help you relax (sedative) or a medicine to treat anxiety.
• If you have trouble staying still for long periods of time.
• Whether you are pregnant or may be pregnant.

What are the risks?

Generally, this is a safe test. However, problems may occur, including:

• Bleeding, pain, or swelling at the injection site.
• Allergic reactions to the radioactive material. This is rare.

What happens before the procedure?

• Do not eat or drink anything after midnight on the night before the procedure, or as directed by your health care provider.
• Take medicines only as directed by your health care provider.
• Tell your health care provider if you are pregnant or breastfeeding.
• If you have diabetes, ask your health care provider for diet guidelines to control your blood sugar (glucose) levels on the day of the test.

What happens during the procedure?

• An IV will be inserted into one of your veins.
• A small amount of radioactive material will be injected into a vein.
• You will wait 30–60 minutes after the injection. This allows the material to travel through your body.
• You will lie on a cushioned table, and the table will be moved through the center of an imaging machine similar to a CT scanner.
• Pictures of your body will be taken. It will take about 30–60 minutes for the machine to produce the pictures. You will need to stay very still during this time.

What happens after the procedure?

• Ask your health care provider, or the department that is doing the test:
  • When will my results be ready?
  • How will I get my results?
  • What are my treatment options?
  • What other tests do I need?
  • What are my next steps?
• You may resume your normal diet and activities.
• Drink 6–8 glasses of water after the test to flush the radioactive material out of your body. Drink enough fluid to keep your urine pale yellow.

Summary

• A PET scan is a test that creates pictures of the inside of the body. PET stands for positron emission tomography.
• For this test, a small dose of a harmless radioactive material is injected into a vein. It will travel through your body in 30–60 minutes.
• While lying down and staying very still, you will be moved through a machine that takes pictures of your body. This will take 30–60 minutes.
• The colors and brightness on the pictures show different levels of organ and tissue function. For example, cancer tissue appears brighter than normal tissue on a PET scan image.