Positron Emission Tomography (PET) Scan

Positron emission tomography (PET) is a diagnostic test. It can be used to examine organs such as the heart and brain. It can also look at body tissues such as lymph nodes. Rather than showing the structure of a body part, PET images show the chemical function of an organ or tissue. PET can show changes in how an organ or tissue works. This can help your healthcare provider diagnose problems and develop a treatment plan for you.

Why a PET Scan Is Done

PET scans are often done to help diagnose or manage conditions including:

• Coronary artery disease

• Brain tumors

• Cancer

• Seizure disorders

• Memory problems

• Stroke

• Brain diseases such as Alzheimer’s, Huntington’s, or Parkinson’s

Preparing for a PET Scan

You will be told how to prepare for your scan. Follow these instructions carefully. In general:

• Do not eat for 6 hours before the scan. This includes gum and mints.

• You can and should drink plenty of water before the scan.

• Tell your healthcare provider what medications you take and ask if you should take them as usual before the exam.

• Tell your healthcare provider if you are, or may be, pregnant, or are breastfeeding.

• Tell your healthcare provider if you have diabetes. You may be given special instructions.

During the Procedure

• Tell your healthcare provider if you tend to be claustrophobic. You may be given a sedative to help you relax.

• You will be given a radioactive compound through an IV (intravenous) line. While your body absorbs the compound, you will be asked to rest quietly on a table or in a reclining chair for 30–60 minutes. Once the compound is absorbed, the scan can be done.

• For the scan, you will lie on a cushioned table. The scan itself takes 30–90 minutes. During that time try to stay as still as possible. Move only when told.

After the Procedure

If you were given a sedative, have an adult friend or family member drive you home. Over the next several hours, drink plenty of clear fluids to help flush the radioactive compound out of your system. Know that the radioactive compound will pose no danger to your loved ones.

Risks of a PET scan are minimal. Ask your doctor to explain them to you.