An MRI (Magnetic Resonance Imaging) machine or scanner uses a powerful magnet and radio waves to take very clear and detailed pictures of the body. It is useful for looking at many parts of the body and often gives extra information to plain X-rays, ultrasounds or CT scans. During an MRI scan, the part of the body being scanned will have images taken from several different angles. The magnetic field used in MRI is believed to be safe even for unborn babies. There is no ionizing radiation (e.g. X-rays) used in MRI.

Why does my child need an MRI?

Your child may need a MRI for many different reasons, for example to:

• look at the shape or structure of parts of the body
• check for any signs of disease
• help plan follow-up treatment after a procedure
• help with planning before an operation
• for early detection, treatment, and management of diseases

MRI scans can be performed on any organs within the body.

Preparing your child for their appointment

For some ideas on how to prepare your child for the procedure, and tips on distracting them and helping them stay calm during the procedure, see our fact sheet Reducing your child's discomfort during procedures. 

It may be helpful to your child if the procedure is explained to them before they come in for their important. Explain that: 

• the scans are painless
• a parent or carer can stay with the child during the scan

Most children can watch a movie while having their scans, and you are welcome to bring in your child's favourite movie or TV show to keep your child occupied and distracted during the scan. 

Specialist staff from Child Life Therapy may also be of benefit for your child. The Child Life Therapist engages families in imaging-specific education and medical play, as well as providing distraction and support during procedures. Child Life Therapist’s also run a Mock MRI clinic which allows patients undergoing awake MRIs to learn about what is required, and to experience a simulated MRI prior to their actual MRI booking. Appointments for Child Life Therapist support can be made in advance via Medical Imaging or your referring doctor.

What to expect with an MRI scan

Before the MRI scan

Prior to your child’s scan the MRI technologist will invite you into an interview room and ask a series of questions of you and your child. All people entering the MRI room need to fill out a MRI questionnaire before the scan. It asks about their medical history and helps the MRI staff ensure the safety of all persons in the MRI room. It is very important that this questionnaire is filled in accurately.

The MRI magnet may affect some medical devices that have been implanted inside your child’s or your body. These include older style pacemakers, implanted defibrillators, various nerve stimulators, infusion pumps and embolisation coils. In general, all body piercings and other jewellery must be removed, due to the metal in the piercing affecting the quality of the scan.

Your child may be asked to change into a hospital gown before their scan. If they would prefer not to wear the hospital gown, wearing a plain T-shirt and shorts or leggings may be OK, however articles of clothing will have to be removed if they contain metal, decoration, or glitter as they will affect the pictures.

During the MRI scan

For all examinations, a family member or carer is encouraged to stay with your child to help them feel comfortable about the procedure and to help them to remain still. The MRI scanner is like a big square box with a tunnel through the middle.

During an MRI your child will have to lie very still in the tunnel, usually on their back. The MRI machine makes some loud knocking noises which change during the study. It is generally only the noises made by the machine that people are aware of during the imaging but occasionally they may feel a little warm. The table your child will lie on is quite narrow and foam cushions and soft straps are used to help your child remain safe and to remain still during their scan.

Depending on the examination some extra pads may be placed around or over your child’s body. They can watch their chosen movie and see around the room through mirrors that are positioned above their head, and they can hear and talk to the MRI technologist performing the scan through headphones and a microphone. The scan time will vary depending on which or how many parts of the body are being examined, but will usually take 25-45 minutes.

MRI with contrast

A report will be prepared by the Radiologist and sent to the referring doctor. Due to the high detail and number of images acquired during an MRI, it may take a long time for the MRI to be reported. The report is often available within a week but can be received earlier if required. If you have any questions about why your child needs a MRI scan, or questions about the results of your scan, please speak to your doctor.

After the scan

If your child has not had IV contrast, sedation or general anaesthetic, you will be able to leave straight after the MRI scan.

If IV contrast was needed, your child will be observed for 10 minutes after the scan. It is very rare for a child to have an allergic reaction to the contrast, but if a reaction does occur staff are well trained to manage any adverse events associated with contrast.

MRI scans have many pictures with a lot of detail, so they often take a long time for the radiologist (medical imaging specialist) to review and report on. The technologist performing the study will not be able to give you any information about the imaging findings at the time of the examination.

Clerical staff cannot give out results over the telephone. If you have any questions about the results of your MRI scan, speak to your doctor.

Key points to remember

• MRI scans use a powerful magnet and radio waves to create high detail, cross-sectional images of the body.
• MRI scans do not use any ionizing radiation, are very safe, with no adverse effects expected
• A parent or carer is encouraged to stay with their child during the MRI scan
• Sometimes contrast will be required for MRI scans
• Sometimes MRI scans need to be performed while your child is under sedation or general anaesthetic
• You can leave the department straight after a MRI scan

For more information

• Kids Health Info fact sheet: Reducing your child's discomfort during procedures 
• Be Positive: A child's guide to hospital: MRI
  
• The Royal Children's Hospital: Okee in Medical Imaging app 
• Child Life Therapy Service: Medical Imaging
• Kids Health Info fact sheet: Sedation for procedures 

• Talk to your doctor or the MRI staff

Developed by The Royal Children's Hospital Medical Imaging department. We acknowledge the input of RCH consumers and carers.

Reviewed November 2018.

This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.

Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit www.rchfoundation.org.au.