Cerebral Perfusion Scan Factsheet

Introduction

A Cerebral Perfusion scan shows how well blood flows through your child's brain.

It uses:

a Gamma camera - a large camera that measures radiation
radiotracer – an injection of radioactive fluid that moves through the body.

The gamma camera shows the radiotracer moving through the brain.

A Cerebral Perfusion scan helps doctors to:

find areas of the brain that are causing seizures
check for cerebral ischemia – reduced blood flow in the brain
check brain injuries.

Before the scan

Your child can eat and drink normally before the scan.

Your child will have an intravenous (IV) cannula inserted into their vein before the scan. They will also be weighed to help calculate the correct amount of radiotracer.

The risks of radiation and allergic reactions are very low. Let your child’s treatment team know if they have any allergies.

Numbing cream

Needles can be uncomfortable for children. Numbing cream can be used on children over two years old.

If your child needs numbing cream, you will need to:

ask for it before the day of the scan
arrive 30 minutes early to the appointment so it has time to work.

During the scan

The scan takes about 1.5 hours; you can stay with your child.

Your child will not feel anything during the scan, and the camera will not touch them.

Generally, the steps of the scan are:

an IV cannula is inserted into your child’s vein
your child will rest for 20-30 minutes in a dimly lit room
a small amount of radiotracer is injected through the IV cannula
your child will rest again for 20 minutes while the radiotracer moves through their body
they will then get up to do a wee to empty their bladder
when they are finished, they will lie down on the scanning bed
velcro straps may be used to gently secure them to help them stay still
some white tape may be placed on their forehead and chin
the cameras will spin around their head for about 30 minutes to create 3D images.

Scan for epilepsy

Children who are being assessed for epilepsy may need two scans, two days apart.

One scan is done while they are taking their anti-epileptic medication, and the other scan is done without the medication.

Scan for Cerebral ischaemia

Children who are being assessed for cerebral ischaemia may need two scans, two days apart.

The first scan is normal. The second scan is done after taking medication to widen the cerebral blood vessels before the radiotracer.

The images from both scans are then compared.

CT scan

Some children may need a low-dose computed tomography (CT) scan towards the end. CT scans use X-rays to take a detailed picture of the inside of the body.

The CT scan will take around two minutes. Because of the X-rays, parents and carers must leave the room for this scan.

After the scan

You can leave once the results are checked by a doctor or nuclear medicine scientist.

The results will be sent to your child’s doctor within a couple of days. You will need to schedule a follow-up appointment with your child’s doctor to discuss the results.

Management

Radiation

Your child will be exposed to a small amount of radiation during the scan. The benefits of finding and treating kidney problems are greater than the small risk of this low dose.

Allergic reactions

Allergic reactions to radiotracer are very rare and usually mild. Your child’s doctor will talk to you about any potential risks before the scan. Let your child’s treatment team know if they have any allergies.

Supporting your child during the scan

Scans can be uncomfortable for children. You can prepare your child by:

explaining to them why the test is needed in simple words
bringing along their favourite comfort objects, like a blanket, toy, or dummy
arriving 30 minutes before the appointment if your child needs numbing cream.