Magnetic resonance imaging (MRI) is a type of scan to get a detailed picture of the inside of your body.
What is magnetic resonance imaging (MRI)?
Magnetic resonance imaging (MRI) is a type of scan used to get a detailed picture of the inside of your body.
- It uses strong magnetism, radio waves and a computer
- It does not use radiation (X-rays).
MRI cannot diagnose prostate cancer on its own. You will usually need to have a prostate biopsy as well.
- Watch this video from Cancer Research UK to find out what it is like to have an MRI scan.
© Cancer Research UK  All rights reserved. Information taken 21/03/23. Cancer Research UK are independent from Prostate Cancer Research.
Important things to know
Why do I need an MRI scan?
Doctors use MRI scanners to look for any suspicious areas in:
- Your prostate
- The area surrounding your prostate.
If they think that cancer may be present, they may recommend you have a prostate biopsy.
- A standard MRI scanner is a large, cylinder-shaped tube. You will be asked to lie on a table that then slides into the tube.
- Some people can feel shut in (claustrophobic) when inside the tube. If you think you may have a problem, contact the radiography department, or tell your doctor. Your doctor may prescribe you some light sedation. This will help you to relax.
- You will not be able to go into an ‘open’-type MRI scanner. This is because the magnetic field strength is lower than in closed MRIs. This means they will not give a clear enough picture of your prostate.
- MRI scans can be very loud. You may be given some ear plugs or headphones to wear before going into the scanner.
- A multi-parametric MRI (mpMRI) works by producing more detailed pictures of your prostate than a normal MRI. This means that your healthcare team can:
- See any suspicious areas more easily.
- Decide whether you need to have a biopsy of your prostate.
- Target biopsy needles more accurately. This can reduce the number of samples that are taken from your prostate at one time.
- See if there are any suspicious areas outside your prostate. For example, in lymph nodes or bones in your pelvis.
- It is often done before you have a prostate biopsy.
- mpMRI is now the ‘gold standard’ recommended type of MRI. But it is not available in every hospital. You can talk to your doctor about mpMRI.
- Our services search tool (link will open in a new tab) will allow you to search for hospitals near you that offer mpMRI.
What do I need to do?
- You may be asked to empty your bowels before your MRI. Your appointment letter should tell you about any preparation you need.
- Some metals interfere with the magnetic field of the MRI. They may damage some of your belongings. Before going to the MRI room, you will need to remove:
- Watches, including electronic watches and GPS trackers
- Mobile phones
- Body piercings
- Removable dental devices such as, braces
- Credit cards
- Hearing aids.
- The radiographer will go through a safety checklist with you before you can have your MRI. You need to tell them about any metalwork that you have inside your body. This includes:
- Cochlea implants
- Surgical clips, coils, pins or plates
- Dental fillings or bridges
- Any other metal fragments.
- Having any of these devices does not necessarily mean you will not be able to have an MRI. If you got a leaflet after having an implanted device, it may mention MRI. If you have these leaflets, bring them with you to the scan.
What is contrast medium?
- You may have to have an injection of special dye. This is called a contrast medium.
- This will give a clearer picture of your prostate.
- You may also be given an injection that will stop bowel movement. This is called Buscopan (hyoscine butylbromide).
- Before you have the injections, tell the radiographer about any:
- Allergies that you have
- Medical conditions that you have.
- The radiographer will put a small tube into a vein on the back of your hand or in your arm. This is called a cannula. The radiographer will use this to inject the dye and the Buscopan.
- Your test results may take one-to-two weeks to come back.
- A radiologist will look at your scans and give them a score.
- You may hear your doctor talk about the Likert score or the PI-RADS score.
- These go from one-to-five and tell you how likely it is you have prostate cancer. This will help your doctor decide what to do next.
About this information
- This information was published in March 2023. We will revise it in March 2024.
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