Magnetic resonance imaging (MRI) uses strong magnetic fields and radio waves to take very detailed pictures from almost every angle to produce two and three-dimensional images of the inside of your body. An MRI scan is painless and harmless
What is it used for?
It is often used to examine your brain and spinal cord, bones and joints, breasts, heart and blood vessels. It can also be used to examine other internal organs such as your lungs or liver.
Do I need to prepare?
Sometimes you will be asked not to eat or drink for several hours beforehand. You also need to remove any metal objects from your body such as watches, jewellery, piercings, false, teach and hearing aids.
Someone on the team providing your care will explain what to do if you do need to prepare.
What happens during the procedure?
The scanner is a large tube that contains a series of powerful magnets. You lie on a flat bed, which is moved inside the tube during the scan. You must stay very still during the scan, which will take between 15 and 90 minutes.
The scanner is quite noisy and makes loud clicking sounds, so you will be given earplugs or headphones to wear. It is in a separate room from the computer that controls it, but you will be able to talk to the radiographer carrying out the scan through an intercom and they will be able to see you on a TV monitor.
Some people feel slightly claustrophobic ('closed in') when they are inside the scanner. If you are worried this may happen, please tell us beforehand and we may give you a sedative to help you relax.
NHS Choices explains more about MRI scans.