PET/CT Scan (Positron Emission Tomography/Computed Tomography)
Name: __________________________________ MR:___________________
Date: ______________________________ Time: ______________
- If you have any questions about these instructions or about the PET/CT Scan please call
- 608-265-8731 Monday through Friday 800AM – 400PM.
- Do not eat or drink anything for 6 hours before your test (including gum).
- If you take medicines every day, take them with a small sip of water.
- If you have been told not to take your medicines on an empty stomach please do not eat more than 2 or 3 soda crackers within 4-6 hours of your exam.
- If you have diabetes please let us know ahead of time so we can work with your doctor to find the safest way for you to get ready for your test.
- If you have any problems with claustrophobia or pain, your doctor may prescribe medicine to help you relax and make you comfortable during your exam. If medicine is prescribed you must arrange for someone to drive you home.
- If possible, do not wear jewelry or clothing containing metal.
- If you are pregnant or breast feeding let us know.
- Please bring your MRI or CT films with you if they were taken at a hospital or clinic other than UW Hospital.
Why do I need a PET/CT Scan?
A CT or MRI scan tells the doctor what an organ looks like and where a tumor is. A PET/CT scan shows how cells and organs in your body are working. A PET/CT scan can measure how much energy a tumor is using. Scar tissue and tumors that have responded to chemotherapy or radiotherapy do not use much energy. Cells and tumors that are growing or active use a lot of energy. A PET/CT scan can help tell the difference between these types of cells. It is often able to find cancer that has spread to other parts of the body.
What is a PET/CT Scan?
A PET/CT scanner is a special camera that can take pictures of the inside of your body by sensing a radioactive tracer. For most studies, this tracer is a radioactive glucose (sugar). Before your PET/CT scan, you will be given an injection of a small amount of radioactive glucose. Cells in the body absorb glucose at different rates. The PET scan can measure how much radioactive glucose is being used. This reflects the cells’ metabolism. A PET/CT scan may find disease before it shows up on other tests. It can tell doctors how a disease responds to treatment.
Our PET Scanners are PET/CT Scanners. This means the PET and CT Scanners are combined as one scanner. Most of the PET Scans will use the CT with a very low radiation setting to create a map of what your organs look like to help the doctors interpret your PET Scan.
When is a PET/CT scan used?
- Epilepsy: to show seizure focus (where the seizures are coming from).
- Alzheimer’s disease: to show areas of reduced glucose metabolism.
- Parkinson’s disease: to show areas of reduced function.
- Brain Tumors: to see if recurrent tumor is present.
- Cancer: to show areas of increased glucose metabolism for staging.
- Heart problems: to show blood flow and metabolism.
What happens when I come for the test?
You will receive an injection of a radioactive tracer. The length of time between the injection and the scan depends on how long it takes the tracer to get to the part of your body being scanned. Most often, this will be 45 minutes to an hour. If you are having a heart study you may not need to wait at all. During the waiting time you may not read, talk or listen to music. For some exams you may be asked to wait in a quiet dimly lit room so as not to stimulate your brain by reading or talking.
What is the scan like?
You will lie on a table that moves slowly through the ring-like scanner. You must lie very still because movement can effect the test. You should feel normal during the test. The CT Scan part is first and takes about 5 minutes. The PET Scan part is second and takes about 35 minutes. The total exam time from injection through scan can take 30 minutes to 2 hours.
How long will I be at the hospital?
Plan to spend 2-3 hours here. The length of the actual exam varies depending on what the doctor needs to see.
What happens after the scan?
You may leave as soon as the scan is complete. You will be able to eat and drink right away unless you have been told not to. Drink a lot of fluids the day of the test to help clear the tracer from your system.
Are there any risks in having a PET/CT Scan?
The radiation you receive is about the same as what you would receive from a bone scan, a test often done in Nuclear Medicine. The radioactive tracer does not remain in your body for very long. There is no reason to avoid being around other people once you have left. To be extra safe avoid being around infants or women who are pregnant for a couple of hours after the scan.
The Spanish version of this Health Facts for You is #6705.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 02/07/2013
Copyright © 02/07/2013 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#5599
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