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Positron Emission Tomography (PET) Scan

What is a PET scan?

A PET scan is a non-invasive test which uses a special dye to show the chemical and functional changes within the body. The special dye is called fluorodeoxyglucose (FDG) and it acts similar to sugar. Growing cells in the body use sugar as a primary source of fuel. The faster the cells grow, the more sugar is needed. The FDG goes to the parts of the body which are very active. Special pictures are taken after the FDG is injected into a vein (IV). The pictures show this medicine in the active tumors and are taken 1 hour after injection of the FDG.

What should we do before the scan?

In preparation for the PET scan, please eat a normal diet with moderate amounts of sugar and carbohydrates the day before the PET scan. 
Avoid smoking, caffeine, gum chewing, or exercise for 24 hours prior to the scan. For the 4 hours before the scan, do not eat or drink (except plain water). Your child’s blood sugar will need to be checked before the scan. This will be done either at Children’s Minnesota or Abbott Northwestern Hospital.

You may keep your child’s routine sleeping and medicine schedules before the test. Your child’s doctor or a Children’s staff member may give you different instructions if your child will have sedation or more tests on the same day.

You may want to bring your child’s favorite book, toy, or comforting object for the scan.

Can I be with my child during the test?

You are welcome to stay with your child during the whole test. However, if you are nursing or pregnant it is not recommended due radiation exposure. It is also not recommended to have any siblings at PET scan.  If your doctor has ordered sedation for your child’s scan, plan on being at Abbott for a total of 3 to 4 hours. See the education sheet Propofol (Diprivan) for sedation.

How is the scan done?

This scan is done in the Nuclear Medicine department at Abbott Northwestern Hospital. An Abbott Nuclear Medicine technician will take you and your child back to a waiting area. Your child will be asked to empty their bladder and remove any metal objects before the scan. The scan has three parts:

  1. Injection: Your child will have an IV placed in a vein, usually in the arm or hand. This involves a little poke. Once the IV is in place, the needle is removed and a tiny plastic tube stays in the vein. The FDG is given into the IV. If your child has an implanted Port-a-Cath, Hickman, or Broviac, the FDG can be injected into this existing line instead of placing an IV.
  2. Waiting period: Your child will need to lie still for 45-60 minutes while the FDG is being distributed throughout the body.
  3. Scan: After the waiting period is complete. Your child will be taken to the PET scanner for the scan. You will see the large scanning machine with an opening in the middle (looks like a doughnut hole). Your child will lie on an imaging table, which moves in and out of the opening smoothly. The Nuclear Medicine technologist will secure your child to the imaging table with soft wraps and blankets. The room lights will be dimmed during the scan. The scanner does not touch your child. It makes whirring sounds as it takes the pictures. This scan will last 20-30 minutes.

What can I expect after the test?

If your child was sedated for the scan they will be monitored by a nurse in the recovery room until they wake. You may be with your child while they are recovering from sedation.

Your child may go back to normal eating and activity after this test.

Your child should avoid getting close to an infant or anyone who is pregnant for 8 hours immediately following the scan. Your child should stay at least 3 feet away from any siblings under the age of 5 and should not share the same bed until the FDG is eliminated from the body. The small amount of FDG used for the test will naturally lower over the next 24 hours. You and your child will not notice any differences. Drinking plenty of water will help flush the FDG from your child’s body.

You will receive the scan results from the doctor who ordered the test.

How should I prepare my child?

Children are usually less afraid and feel more successful when they know what to expect and what is expected of them. You know your child best. The amount of detail you give will depend on your child’s age and developmental level, reactions to previous health care experiences, and degree of anxiety about this test. Talking about it can help your child be more comfortable with the test, which will make the test easier for both of you.

For many children, a big concern is whether or not the test will hurt. Assure them there may be some discomfort which will only last a few moments. Remind them the test is important because it helps find out how their body is working inside.

Children and young adults of all ages may want to bring a comfort item, such as their own blanket and pillow.  Younger children may also find it helpful to bring a favorite toy or pacifier.  Older children and teens may want to bring an electronic device.

To learn more about preparing and helping your child cope with this test, call the child life department. Child life specialists are trained to help children understand and cope with medical producedures and can offer parents advice on how to talk with and support their child. There is no charge for child life services.

Child life department phone number:

Children’s-Minneapolis (612) 813-6259


This sheet is not specific to your child but provides general information. If you have questions or need more information about the test, call the Nuclear Medicine department at Abbott Northwestern Hospital (612) 863-6665.

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This page is not specific to your child, but provides general information on the topic above. If you have any questions, please call your clinic. For more reading material about this and other health topics, please call or visit Children's Minnesota Family Resource Center library, or visit

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