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MRI scan – information for parents

What is an MRI scan?

MRI stands for magnetic resonance imaging. 

An MRI scan uses a combination of a strong magnet and radiowaves to produce detailed pictures of the inside of the body. It can help to find out what is causing your child's problem and help your doctor to find the best treatment.

It provides much more detailed pictures of your child's body than an ordinary x-ray. It is particularly good at identifying problems in the spine, brain and the joints. It is also helpful for looking at other parts of the body, often when other types of scan have not given a full picture.

Unlike x-rays and CT (computerised tomography) scans, MRI scans do not use radiation. 

MRI scans under general anaesthetic

Please see our separate page if your child needs to have an MRI under general anaesthetic. Children under 10 years of age usually need an anaesthesia for a heart scan.

Having an MRI scan while awake

The information below relates to children having an MRI scan while awake. 

Preparing for the scan

Are there any risks?

MRI is a very safe procedure for most patients. However patients with heart pacemakers and certain other surgical implants, for example a cochlear implant, cannot be scanned. 

You will be asked to complete and sign a safety questionnaire for your child before their scan to make sure it is safe for them to be scanned.

You will also be asked to complete and sign a safety questionnaire for yourself in order to make sure it is safe for you to go into the MRI room with your child. 

Before your child's MRI scan

If we need your child to do anything special in preparation for their scan we will send you information about this with your appointment letter.

Routinely your child can:

  • eat and drink as normal and continue to take any medications he/she has been prescribed
  • bring a CD to listen to during the scan or a favourite toy to take in with them (providing it does not contain metal)
  • bring a DVD to watch as sometimes it is possible to watch a film during the scan.

Before entering the scan room:

  • you will need to complete an MRI safety checklist for you and your child
  • the radiographer (member of the radiology team trained to carry out scans) will explain the scan and answer any questions you have.

You and your child will need to empty your pockets and remove all loose metal objects like watches, keys and coins, as well as any credit cards or travel cards with magnetic strips, as the scanner can stop these from working. We provide lockers outside the scan room for these items.

If there are any zips or metal fastenings in the area we are going to scan, your child will need to change into a hospital gown as metal can spoil the pictures. 

During the scan

We will ask your child to lie on the scanner bed and keep very still during the scan. Any movement can make the pictures blurred and the scan may have to be repeated.    

Once your child is positioned correctly, we will move them into the scanner – the part of your child's body that we are scanning must be in the centre of the machine. The scanner is a short tunnel. The radiographer will talk to your child during the scan to let them know what is happening and your child will be given a buzzer to press if they need to attract our attention during the scan.

When the scanner is working, it makes a loud banging noise. We will give you and your child headphones to wear, to reduce the noise.

The scan should be completely painless. Sometimes the scanner bed vibrates slightly due to the noise. This is quite normal and is nothing to worry about.

The most difficult part is keeping still. Please help us to make sure your child is as comfortable and as relaxed as possible before we start.

Most scans take between 20 and 40 minutes. 

Will my child need an injection?

If we are scanning certain areas of your child's body, we may need to give them an injection of contrast dye. This shows up on the scan and gives us more detailed pictures, particularly of your child's blood vessels.

If we know your child will definitely need an injection an additional information sheet will be included with the appointment letter.  

Noises during the scan

The MRI scan is quite noisy. When the scanner is working, it makes a loud banging noise. It's a bit like hearing roadworks or travelling on the underground. We will give you and your child headphones to wear, to reduce the noise. Your child will be able to listen to music through the headphones and sometimes watch a DVD during the scan. 

You can listen to some of the noises your child may hear during the MRI scan.  

MRI sounds one

MRI sounds two

MRI sounds three

MRI sounds four

After the scan

As soon as the scan is finished, you can go home or back to the ward, if your child is staying in the hospital. Your child can eat and drink as normal and go back to their usual activities.

The pictures taken during the scan are carefully studied by the radiologist (doctor trained in reading MRI scans to diagnose and treat illnesses), who will produce a detailed report. This will be sent to the doctor who referred your child for the scan. The results should be available to you at your next clinic appointment. 



For general enquiries call the MRI reception on 020 7188 9218.

For appointment enquiries please contact one of the below:

  • MRI appointments - 020 7188 7188 extension 58360
  • heart MRI appointments – 020 7188 7188 extension 50863

How to find us

Level 1 – Arctic (penguin and igloo zones)
Evelina London Children's Hospital
Westminster Bridge Road
London SE1 7EH

How to get to Evelina London

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