An MRI scan uses a magnetic field rather than X-rays to take pictures of your child’s body.
What is an MRI scan?
MRI stands for ‘Magnetic Resonance Imaging’, which means that a picture is taken of the inside of the body using a strong magnetic field rather than X-rays. They’re used to get detailed pictures of part of the body which can then be used to plan treatment.
The MRI scanner is a hollow machine with a tube running horizontally through the middle. To have the scan, your child will lie on a bed that slides into the tube. You’re welcome to stay with your child during the scan - but if you’re in the first three months of pregnancy please tell us beforehand.
When you arrive at the hospital
You should go straight to the MRI department on level 1 of The Variety Club Building.
Before the scan, we need to ask you some questions and check that you and your child are not wearing any metal like earrings, or belt buckles, or have any metal implants inside the body. As the MRI scanner creates a strong magnetic field, wearing any metal inside of the room could be dangerous. We’ll ask you to sign a form confirming this.
Once we have done the metal check, we will take you and your child into the scanning room. Your child will lie on the bed and depending on the part of the body being scanned might need to wear a coil over that part. When your child is in the correct position, the radiographer will move the bed into the scanner tube and go into the control room. You and your child will be able to talk to them over the intercom system.
Once the scan starts
The scanner will make a continuous knocking sound which can be quite loud, but we will give you and your child ear protectors. As well as the knocking sound, the scanner will make occasional louder noises - but the radiographer will warn you before it happens.
The scan will last between 20 minutes and an hour. When it is finished the radiographer will come back into the room and move the bed out of the scanner. Your child will be able to get off the bed, and you’ll be free to go home unless you have any other appointments planned.
You will not get the results of the scan straight away as the doctor needs to write a report about it and send it to your own doctor – usually in time for you next appointment.
Having an MRI under sedation:
Your child will need to lye very still for the MRI scan, so we may suggest that they have some sedation to help to make them sleepy and less likely to move about. The evening before the scan it can help to reduce the amount of sleep that your child has by letting them stay awake for an hour or two longer. You can then wake them an hour earlier the next morning – and keep them awake on the way to GOSH. This will make your child sleepy and help with the sedation.
Your child will need to stop eating and drinking some time before the sedation is given.
• Breastfed babies should have their last feed two hours before the appointment time.
• Children under one should have their last milk feed or solids four hours before appointment time (clear fluid such as squash or water are allowed until two hours before the appointment time).
• Children over one should have their last food or milk drink four hours before the appointment time (clear fluid such as squash or water are allowed until two hours before the appointment time).
These instructions will reduce the risk of vomiting under sedation.
Sedation is given as a liquid to swallow, so if your child has any swallowing difficulties please let us know beforehand. Some children need to have the sedation topped-up with an injection before the scan. We will put some local anaesthetic cream on your child’s hand to numb it – just incase an injection is needed. After the scan is finished, be prepared to stay in the department until your child is fully awake and has had something to eat and drink. Most families are able to go home a couple of hours afterwards.
Children are generally sleepier than usual for the first 24 hours because the effects of the sedative last for about a day. If your child is unduly sleepy or difficult to rouse, make sure they are in a safe position on their side and call your family doctor. Make sure that your child can cope with a juice drink before you give them anything to eat. Only give milk if your child doesn’t feel sick or vomit.
Your child might be irritable after sedation – this is normal. Keep a close watch on your child until they have recovered and don’t leave them with an experienced carer. Give your child’s regular medication s normal. Your child should be well enough to go to school the day after the MRI scan. If you have any questions, please contact the MRI department on the number in your appointment letter.
Ref: 2010F0627 © GOSH Trust July 2010 Compiled by the Radiology Department in collaboration with the Child and Family Information Group.