MRI scans

A Magnetic Resonance Imaging (MRI) scanner uses a magnetic field and radio waves to build up pictures of parts of the body by picking up signals sent out by water molecules

Across both Chelsea and Sutton, The Royal Marsden has five MRI machines, three 1.5T machines and two 3T machines, including one which is exclusively for clinical research in Sutton. We are one of the few centres in the UK to offer high quality whole body imaging. Our MRI capacity has increased over the past year, with the refurbishment of the Reuben Foundation Imaging Centre in Chelsea, funded by supporters of The Royal Marsden Cancer Charity.

What preparation will I need?

Usually there is no preparation required for an MRI scan. You may eat and drink normally before and after the scan unless you have been told otherwise.

For abdominal and pelvic scans you may be given medication before the scan. This will relax your bowel for a short time to improve the quality of the scan. All instructions will be on your appointment letter – please read it carefully.

An injection of contrast medium (dye) may be given into a vein. This is not always necessary but it can provide the scan with extra information. As with all medication, a very small number of patients may be allergic to contrast medium. Please inform the radiographer if you have any allergies or you are breast-feeding.

What happens when I come for a scan?

When you come for your appointment it is advisable to wear clothing without metal fastenings. Alternatively, we can provide a hospital gown or pyjamas.

You will not be allowed to take or wear anything metallic or with magnetic strips into the scan room, except a wedding ring. You may wear your spectacles, but they will be taken off immediately before the scan.

A locker is provided for your valuables. You must give the key to a radiographer as it is magnetic.

Who will I see when I have my scan?

As well as meeting reception staff, you will also meet radiographers who are trained to carry out the scans. You may also see a radiologist (a specialist doctor who is trained to interpret the results and carry out some of the more complex examinations).

Does the scan hurt?

No, the scan isn’t painful. However, you will have to lie still for up to one hour on a table which is quite hard. The radiographers will do their best to make you comfortable. If you have any pain or discomfort that could lead to difficulties with the scan, please tell the radiographer before your scan.

What happens during the scan?

The scanner produces a variety of loud noises which are made by magnetic coils that switch on and off during the scan. These coils measure the signal coming from your body in order to create the images. The noise is caused by them being switched on and off so rapidly that they vibrate.

Ear defenders or earplugs will help reduce this noise.

Although the scanner is open at both ends, some people may find it slightly claustrophobic. If you are worried about this, please speak to your radiographer before you come for your scan. During the scan, the radiographer will be able to see you from the control room and you can talk to each other through an intercom. You will be given a call button to press and may be able to listen to music during the scan. The newer scanners are much shorter and wider than before.

A variety of videos about what to expect when having a scan can be viewed on the Royal College of Radiologists website.

How long will the scan take?

Scans can take between 20 minutes and an hour. If your scan is going to take longer you will be told this when your appointment is made.

What happens afterwards?

You may leave the department as soon as your scan is finished. You can also go to the toilet and eat and drink as usual. There are no side affects to the MRI scan itself.

When will I know the results?

Although the radiographer can see parts of your body on the screen, the images must be carefully interpreted by a radiologist who is an expert in this field. He or she will prepare a report and send it to your doctor a few days later.

Your doctor will tell you the results and discuss them with you.

What if I can’t keep my MRI appointment?

If you can’t keep your appointment, please contact the MRI department straight away on 020 8661 3514 (Sutton) or 020 7808 2576 (Chelsea).

If you are admitted to hospital before your appointment, please tell the ward staff that you have an MRI appointment booked.

Where can I get help?

The staff in the MRI department will be happy to answer any questions you may have. Please ask at the time of your appointment or telephone the department at any time on the numbers above.

Further information about MRI scans is available below.

Supported by The Royal Marsden Cancer Charity 

Supporters of The Royal Marsden Cancer Charity donated £6.9 million to fund the 1.5T and 3T MRI scanners and the construction of the MRI suite.

Help us work towards a future beyond cancer.