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Positron Emission Tomography Scan

What is it?

A positron emission tomography (toe-mah-gruh-fee) scan is also called a PET scan. It is a painless test used to look at different parts of your body to see how they are working. It can show how much blood is flowing to an area of the body. And, the scan can show how well the tissues in that area use oxygen and food. It can also show where medicines and chemicals go inside your body.

Why do you need it?

PET scans are done for many reasons. Caregivers may be trying to see if you have an illness or injury, such as epilepsy or a stroke. It can show how far along an illness is, like Alzheimer's or Parkinson's disease. A PET scan may be done to help caregivers decide whether or not you have cancer. It can be repeated often during treatment to see how your treatment is effecting the illness. And, it may be done afterward to measure the results of treatment.

How does it work?

You are given radioactive "tracers" as a dye in your IV or as a gas that you breathe. The tracers are positive particles that give off signals when they combine with the negative electrons in your body. Electrons are tiny positive and negative electrical charges. These charges do many things like help our body use food and medicine. These signals are picked up by the scanner and turned into pictures with different colors. Red means a lot of activity, yellow less activity, and green means even less activity.

Is it safe?

You are exposed to very little radiation. The tracers are very strong but only live for a very short time. Even though the particles are "positively charged" you will not feel electrical shocks. Having a PET scan is safe and cannot hurt you.

During the PET scan:

After putting on a gown, you will be asked to lie down on the table of the PET scan machine. When the test starts, the table moves inside the hole of the PET scanner which is shaped like a doughnut. The PET scanner slowly passes over your body. The scanner records the movement of the tracers in the different parts of your body as signals. A caregiver will either be in the same room or in another room to be able talk to you.

Care Agreement

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.