MRI scan

What is an MRI scan?

An MRI scan uses magnetism to build up a picture of the inside of your body. MRI stands for magnetic resonance imaging.

Why do I need to have this scan?

Doctors might use an MRI scan to show:

  • if a lump or abnormal area is cancer or not
  • the size of the cancer and if it has spread.

What happens?

Before the scan

The hospital sends you information about the scan so you know what to expect. If you are having a scan of your tummy (abdomen), you might be asked to not eat anything for a few hours before the scan. This helps to get a clear picture.

Let your GP know a few days before the scan if it is difficult for you to lie still, or if you get anxious about being in small spaces. They can arrange for you to take a tablet (sedative) before the scan to help you relax.

On the day of the scan, the radiographer will tell you what you need to do. You can ask them any questions you have. You can also tell them if it is difficult for you to lie still, or if you get anxious about being in small spaces. They will give you lots of support.

Because the scan uses magnetism, you will need to remove all jewellery and metal before the scan. This includes hair clips, bra straps and mascara as these can interfere with the scan. Let the person doing the scan (radiographer) know if you have any metal inside your body. This is especially important if you have a shunt or a pacemaker. Some shunts may need to be re-programmed after an MRI.

You can usually wear your own clothes if they do not have metal zips or buttons. Don’t worry if you do not have clothes without metal, you can change into a gown.

You might need to drink a dye called contrast. This is sometimes given as an injection. The dye makes parts of your body show up more clearly on the scan. This can sometimes make you feel hot all over for a few minutes.

During the scan

The MRI scanner looks a bit like a giant doughnut, with a narrow bed that goes through the middle.

The scan is not painful, but lying still on the bed during the scan can be a bit uncomfortable. It usually takes between 15 minutes and an hour. The scanner is very noisy and you will hear a banging noise during the scan.

The radiographer leaves the room during the scan, but can see you through a screen. You will be able to talk to them through an intercom while you are having the scan. You can also listen to music through headphones.

You will need to lie still on the bed as any movement can affect your results. If you get uncomfortable, let the radiographer know. The bed moves slowly through the middle of the scanner (a short tunnel that is open at both ends). Some people find it helpful to close their eyes while they are in the tunnel.

Being positioned for an MRI scan
Being positioned for an MRI scan

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Some tattoos contain metal, especially those with red dye in them. These can cause a warm, or sometimes burning feeling during the scan. This is only in the area of skin where the tattoo is. If this happens, let the radiographer know straight away.

After the scan

You can usually go home straight after the scan.

You will usually get the results within a couple of weeks. Waiting for test results can be a worrying time. Talking to your family and friends about how you feel can help. You can also speak to your doctor or nurse if you have any problems, or need more support.