Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Epilepsy Health Center

Select An Article

Epilepsy and the PET Scan

Font Size

What Is a PET Scan?

A positron emission tomography (PET) scan may be used to locate the part of the brain that is causing seizures. A PET scan is a test used to give doctors and their patients more information about how the cells in the body are functioning.

A PET scan is done by injecting a small amount of radioactive material (known as a tracer) into a patient's vein, usually in the arm. The tracer sends out small, positively charged particles (positrons) that interact with negatively charged particles (electrons) in your body. The PET scanner is able to detect the product of this interaction and uses it to make an image. The PET scan shows the brain's use of oxygen or sugar (glucose).

Recommended Related to Epilepsy

Understanding Seizures -- Symptoms

Symptoms of seizures vary widely, depending on the part of the brain affected by the electrical misfiring. If a very small part of the brain is affected, you might sense only an odd smell or taste. In other cases, you could have hallucinations or convulsions, or you could lose consciousness. Generalized tonic-clonic. This type of seizure is sometimes preceded by an aura (awareness of a strange odor, taste, or vision). You might lose consciousness, fall, and experience muscle rigidity (stiffness)...

Read the Understanding Seizures -- Symptoms article > >

Why Is a PET Scan Used in Epilepsy?

For patients with epilepsy, a PET scan is used to localize the part of the brain that is causing the seizure activity.

However, doctors may request a PET scan for many different reasons. Aside from potential problems in the brain and spinal cord, the test can also be used to diagnose heart problems as well as certain kinds of cancer, including breast, brain, lung, colon, and prostate cancers and lymphoma.

How Do I Prepare for a PET Scan?

Before undergoing the PET procedure, be sure to tell your doctor of any medication -- prescription or non-prescription -- that you are taking, along with any herbal drugs or supplements you may be using. It is also very important that you tell the doctor if you are pregnant or think you may be pregnant, since the PET scan can be harmful to an unborn child.

As the test is about to begin, you will be asked to take off clothing that is covering the area of the body to be tested. Depending on the area of your body being tested, you may be asked to undress completely and put on a hospital gown. You will also be asked to remove any dentures, jewelry, or metal objects during the scan, because these items may affect the reading.

Next Article:

Today on WebMD

human head and brain waves
Causes, symptoms, and treatments.
Grand mal seizure
How is each one different?
marijuana plant
CBD, a plant chemical, may cut down seizures.
prescription bottle
Which medication is right for you?
Seizures Driving
Questions for Doctor Epilepsy
Graces Magic Diet
Pills spilling from bottle in front of clock
first aid kit
Caring Child Epilepsy
Making Home Safe
epilepsy monitoring

WebMD Special Sections