Neuroradiology (MRI/SPECT/PET)
Click here for MRI
information.
What is a SPECT scan?
Single photon-emission computed tomography.
A SPECT scan looks at the blood flow of the brain. This involves
injecting a substance through a cannula in the hand called an
isotope that will travel to the brain and allows us to see if there
are any blood flow changes during a seizure.
There are two types of scan; One (the ictal scan)when the dye is
injected during a seizure and the other (interictal) in-between
seizures.
Please see here for
some more information.
What happens during the test?
Your child will have the EEG wires put in place the day before
the scan.
The nurse or doctor will put a cannula (small plastic tube) into
a vein on your child's hand.
For the Ictal scan the EEG monitoring will continue and a
physiologist will be looking at this recording.
When a seizure occurs they will instruct a specialist
radiographer to inject the isotope (through the cannula).
Once the seizure has finished the EEG wires will be removed and
your child will be taken to the scanner the same day.
The radiographers can carry out the SPECT scan with your child
under sedation, this will be discussed with you before your
appointment.
The scan takes 30 minutes to complete and it is very important
that your child remains still throughout. The SPECT camera rotates
slowly around the head taking images. To get good image quality the
camera needs to get as close as possible, but it will not touch
your child's head.
For the second interitcal scan the EEG will be recorded to make
sure no seizures have occurred before and for 15 minutes after the
injection of the isotope.
As before your child will get an injection into their hand and
taken to the scanner.
Is there any risks to the test?
A very small amount of radioactivity is used to obtain pictures
of the inside of your child's body. This will help the doctors to
understand the nature and extent of your child's illness. The
radiation dose your child receives is very low, and is often less
than from some ordinary x-rays.
What happens after the test?
If medication has been reduced for the test these will be
restarted again and you will be able to go home once they have been
back on full medication for 24 hours and the number of seizures is
back to normal.
If you have any questions please contact the epilepsy surgery
nursing team.