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Common uses for a PET/MRI scan
What is a PET/MRI scan?
This scan combines a Nuclear Medicine PET scan with an MRI scan. The PET/MRI scan shows metabolic changes in the area being scanned. A tracer which is attached to a glucose is injected at the start of the PET scan. Your body uses glucose as its major source of energy, so the tracer collects more in areas of higher metabolic activity and less in areas of lower metabolic activity. The MRI scan shows the structure of the area being scanned. The two scans work together to help find exactly where any abnormal areas are.
PET/MRI allows for a radiation dose reduction of up to 80 percent when compared to PET/CT.
Children’s Hospital of Wisconsin is the only imaging provider in southeast Wisconsin to offer this PET/MRI technology. If a diagnostic MRI is also clinically indicated, patients can come for one appointment and complete both scans, reducing the frequency of anesthesia and travel, and providing more clinical data in a timely fashion.
What to expect during your child’s PET/MRI scan
A PET/ MRI nurse will interview the parent/guardian to get a complete and up to date history.
A blood glucose level will be obtained via finger prick or heel stick. The glucose level must be at or below 200 mg/dl in order for the tracer to be injected. Your child will need to get an IV placed for the injection of the tracer. After the injection, you will need to wait quietly for about 45 minutes prior to imaging. (NO TV, books, iPads) The PET/MRI scanner uses a magnet, so your child will need to take off any metal that he/she is wearing, such as belts, jewelry, earrings and watches. Most braces and fillings in teeth will not be a problem.
Your child must lie very still during the scan. If it is hard for your child to hold still, the nurse may need to sedate your child (give your child medicine to make him or her sleepy).
During the exam, the PET/MRI technologist is able to see your child using a TV camera and will talk to you child throughout the test by using a microphone and headphones. The scanner is noisy, however, your child will not feel anything unusual during the scan. The test should take about 45 minutes.
If sedation is needed, a PET/ MRI nurse and anesthesiologist will monitor your child during the entire exam. In order to provide the best and safest care, parents and guardians are not able to be present in the scan room when sedation is being used.
What happens after your child's PET/MRI scan?
If your child was not given sedation, they may resume normal activities immediately. If your child was given sedation, he or she will be able to leave the hospital a short time after waking up. He or she may still feel sleepy or dizzy for a few hours after the scan. Have your child stay home and rest for the day. Your child may play quiet games, but should not do activities such as riding a bike or climbing. You will receive additional special care instructions if sedation was given to your child.
Your doctor will get the results of the test within 24 hours and will share the results with you and your family.
Preparing your child for a PET/MRI
- If you child does not feel well, it may be hard for him or her to lie still. If your child is sick on the day of the appointment, we may not be able to give your child sedation. Please call the PET/MRI department at (414) 266-3180 if your child is not feeling well. You may need to reschedule your child’s appointment.
- Prepare your child for the possibility that he or she may be given contrast or other medicine through an IV.
- 24 hours before the scan, your child should have foods high in protein (meat and dairy), but low in carbohydrates (avoid starchy, sugary foods and drinks).
- Please arrive 45 minutes before your scheduled appointment time. If you arrive more than 15 minutes past your expected arrival time, your appointment will need to be rescheduled.
- No sibling or pregnant caregivers are allowed to be present with the child during the injection or scanning phase of the exam.
- Your child should have nothing to eat or drink after midnight. Your child can have water up until 3 hours before the appointment time.
- If your child has a condition like glycogen storage disease or diabetes and cannot be without food or liquids for a long time, talk with your child’s doctor about a plan or call (414) 266-3180. Blood glucose needs to be below 200 in order to administer the radioisotope.