PET (Positron Emission Tomography)

PET scans highlight unusual cell activity and are often merged with CT images (referred to as PET/CT) to help target radiation therapy with unprecedented precision. At Northwestern Lake Forest Hospital Diagnostic Imaging Centers, we also use PET/CT to study abnormalities of the brain and heart.

How is a PET scan performed?

You will be asked to lie on a table that is hooked to a large scanner, camera, and computer. The radioactive tracer is usually injected intravenously (IV). The PET scanner, which is shaped like a doughnut, moves around you.

The scanned pictures are sent to a computer screen so your doctor can see them. Many scans are done to make a series of pictures. It is very important to lie still while each scan is being done. The test takes 1 to 3 hours. After the test, drink lots of fluids for the next 24 hours to help flush the tracer out of your body.

For a PET scan of the brain, you will lie on a bed. You may be asked to read, name letters, or tell a story, depending on whether speech, reasoning, or memory is being tested. During the scan, you may be given earplugs and a blindfold (if you do not need to read during the test) to wear for your comfort.

If you are having a PET scan of your heart, electrodes for an electrocardiogram (EKG, ECG) will be put on your body.

How do I prepare for a PET scan?

Talk to your doctor to see if you should stop taking medicines and herbal remedies 24 hours before you have this test. If you take insulin to control diabetes, you may need to take less than your normal dose. Talk with your doctor about how much insulin you should take.

Do not smoke or drink caffeine or alcohol for 24 hours before this test. Do not eat or drink for 4 hours before this test. Tell your doctor if you are or might be pregnant or if you are breast-feeding. Tell your doctor if you have a fear of enclosed spaces or have ever had a panic attack.

 

For more information, please contact your physician or our main Radiology (Diagnostic Imaging) office at (847) 535-6300.