A magnetic resonance imaging (MRI) scan is a type of imaging test – a test that uses special equipment to create detailed images of part of the inside of the body, including organs like the kidneys.

What is a magnetic resonance imaging (MRI) scan?

An MRI scan uses powerful magnets and radio waves to build up a very detailed picture of parts of the inside of your child’s body. It can show things that cannot be seen on an ultrasound scan or X-ray test.

An MRI scanner is a machine that looks a bit like a short tunnel. A bed passes through the tunnel.

Sometimes a contrast dye is used to show parts of the body more clearly. When this is used to look at the urinary system, the test may be called a MR urogram. The dye is injected using a needle. A local anaesthetic, a spray or cream, can be put on your child’s skin before inserting the needle or cannula, to make the area feel numb.

If your child has significantly reduced kidney function, injection of contrast dye will usually be avoided. If dye is needed and your child is having dialysis, their medical team may arrange for them to have a dialysis session after their scan.

Why does my child need this test?

An MRI scan may be necessary when more information is needed to make a diagnosis. Your child may already have had an X-ray test or an ultrasound scan but these may not have provided enough detail.

Are MRI scans safe?

MRI scans are very safe.

The radiographer performing the scan will ask detailed questions to ensure it is safe for your child to have an MRI scan. Anyone who accompanies the child in the MRI scanner room will also be questioned. If your child has any metal in their body they may not be able to have an MRI scan because of the magnets the scans use.

Where will it take place?

The MRI takes place in the MRI department of your hospital.

Who will perform the MRI scan?

A radiographer, a specialist trained in imaging tests, performs the test.

How to prepare your child for an MRI scan?

Your child does not usually need to do anything to prepare for this test, but your doctor will let you know.

Your child cannot wear anything that has metal, such as zippers, buttons or metallic thread on clothes, jewellery such as metal earrings or body piercings, a watch or glasses.

You and your child cannot take anything metal into the scanning room. This includes mobile phones, keys and debit cards.

The radiographer will ask questions to ensure it is safe for your child to have an MRI scan. You should let them know if you or your child has had any operations or if they have any metal in their body.

You will be asked if your child has allergies to any medicines or contrast dye that may be used during the test.

Older girls may be asked if they are having their periods and about the dates of their last menstrual period. They may also be asked if they are pregnant or if they could be pregnant. This is because it is not known if MRI is safe in the early stages of pregnancy.

Some children find it uncomfortable to be inside the scanner. If your child is worried, speak with your doctor. Your child may be able to meet with a play specialist, who can use dolls and other toys to help them prepare for the test.

You may be able to stay with your child during the test. You will be told how long the test will take – this is usually about 20 to 40 minutes, but sometimes longer.

It is very important for the success of this test that children lie very still. Young children and children with developmental delay or learning difficulties find this hard and may need a general anaesthetic so that they are asleep during the scan. The anaesthetic may be given as a gas that your child will breathe in or injected into a blood vessel. If an anaesthetic is needed, your doctor will give you separate instructions, particularly about the time your child should have their last feed or meal before the scan.

What happens during the scan?

If a contrast dye is used, this is given to your child as an injection.

Your child lies on the bed. There may be pillows and straps to help your child feel comfortable and lie still.

The bed moves slowly into the tunnel, so that the part of the body being scanned is in the machine.

Your child needs to lie still while the scanner takes pictures. It can take several minutes to take each picture. Sometimes, your child will need to hold their breath. The radiographer can talk with your child during the scan and let them know what to do.

The MRI is usually very noisy. Your child will be given ear plugs or headphones to wear and they may be able to listen to music during the scan.

What to expect afterwards

Your child can usually go home straight away after the test.

If your child has had a general anaesthetic they will need to stay in hospital for a few hours after the scan to be monitored by their healthcare team.

Getting the results

A report will be sent to your doctor. Speak with your doctor about when you should expect the results.

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