Multi-dimensional scans to investigate many types of different conditions.
You can arrange to have an MRI scan at a Spire Healthcare hospital near you. We provide fast access to diagnostic tests and scans for a wide variety of conditions and symptoms.
15 - 90 minutes
Available to self-pay?
Magnetic resonance imaging (MRI) is a type of scan that uses strong magnets and radio waves to produce very detailed two- and three-dimensional pictures of the inside of your body — in fact, the images produced are the most detailed of any type of scan available today. It does not use ionising radiation as X-rays do.
It’s suitable for every part of the body, including bones, soft tissues (such as blood vessels, ligaments and muscles) and the brain. This means it can help diagnose, plan treatment for and monitor many different medical conditions. Doctors who specialise in analysing MRI scans are called radiologists.
An MRI contrast agent is a special dye used to improve the visibility of certain tissues on an MRI scan. If your doctor recommends that you have an MRI scan with a contrast agent, the agent will usually be injected into a vein in your body. The most common MRI contrast agents contain gadolinium and have been in use since 1983. Since this time, millions of patients worldwide have received gadolinium-based contrast agents before having an MRI scan.
Your doctor may recommend an MRI scan to examine different parts of your body including:
Almost all of our hospitals offer MRI scans. Our fast diagnostics mean you don’t have to wait long for your results.
You can usually eat, drink and take your medications as usual on the day of your MRI scan. However, in some cases, depending on the part of your body being scanned, your doctor may ask you not to eat or drink anything for up to four hours before your MRI scan or conversely, they may ask you to drink a large amount of water just before your MRI scan.
When you arrive for your MRI scan, you will be given a questionnaire to complete about your medical history and health. This ensures your healthcare team are aware of any health issues you're facing so they can complete your scan safely. You will then need to sign a consent form to confirm that you agree to have an MRI scan.
You will be asked to remove all metal objects from your body as the MRI machine uses strong magnets. You will therefore need to remove:
Depending on the part of your body being scanned, you may be asked to change into a hospital gown. If you do not need to wear a hospital gown, you will need to wear clothes that do not contain any metal parts eg metal belts, buckles, buttons, fasteners or zips, or bras with an underwire.
Anaesthesia and sedatives
MRI scans are painless so you will not need any anaesthesia. However, babies and very young children may be given a general anaesthetic before their MRI scan as they can’t usually lie still enough during the scan.
If you are feeling very anxious about your MRI scan or are claustrophobic, make sure you talk to your doctor well before the day of your scan about having a sedative to help relax you.
If you have a sedative during your MRI scan, you will not be able to drive for 24 hours and will therefore need someone to take you home.
An MRI machine has a large cylinder containing a strong magnet, which you lie inside. When it’s turned on, it creates a magnetic field that sends out radio waves. These radio waves affect the water molecules that are in all of your cells.
Water molecules are made up of hydrogen and oxygen atoms. The radio waves affect the hydrogen atoms, specifically an even smaller particle in the centre of the hydrogen atoms called a proton. The protons move slightly so that they all point in the same direction. When the machine is switched off, the protons move back to their original positions and give off signals that are detected by the MRI machine.
The information from these millions of signals can be converted into very detailed images of the part of your body being scanned. Depending on which type of tissue the protons are in, they move back to their original positions at different speeds and give off slightly different signals — this is why different tissues can be distinguished on the images produced by an MRI scan.
What to expect during your MRI scan
For some types of MRI scan, you’ll need an injection of a contrast agent (a special dye), which shows up certain tissues more clearly.
You may be given earplugs or headphones to wear during your scan. You will lie down on a motorised bed that will move into the tunnel part of the MRI machine — the tunnel is open at either end, is well-lit and has a fan to help you feel comfortable. You will either move into the tunnel head-first or feet-first, depending on which part of your body is being scanned, to ensure the part that needs scanning is in the middle of the MRI machine.
An MRI technician will talk to you via a two-way intercom and you can talk back. They will make sure you feel comfortable before the scan starts. You will need to lie as still as possible but you can ask to stop the scan if you need to move or feel very anxious.
A single scan can be captured quite quickly, taking between a few seconds to three to four minutes. For short scans, the MRI technician may ask you to hold your breath. During your scan you will hear noises made by the MRI machine working; these may include banging, beeping, clanging, clicking, tapping and whirring.
Once your MRI scan is complete, you will be moved out of the MRI machine.
If you were given a contrast agent before your scan, the intravenous catheter used to administer the dye will be removed. Most contrast agents contain gadolinium and it is very rare to have an allergic reaction to it. However, if you develop a rash, hives or shortness of breath, let your MRI technician know immediately if you are still at the MRI department. If you have left the hospital, call your doctor or return to the hospital immediately.
If you were given a sedative, you may need to stay at the hospital for a short time until you are fully awake and alert. You will need someone to take you home as you will not be able to drive for 24 hours. You should also not drink alcohol or operate heavy machinery for 24 hours after having a sedative. It is not advised to sign any legal documents during this time either and you should have someone stay with you for 24 hours after your sedative.
An MRI scan is usually an outpatient procedure so you can go home on the same day as your scan. Unless you have had a sedative, you can immediately return to your usual activities.
An MRI scan takes between 15 and 90 minutes depending on the part of your body being scanned. You can go home shortly afterwards.
A radiographer (someone trained to perform scans) will carry out your MRI scan. Afterwards, a radiologist (a doctor trained to read MRI scans) will examine the images. A report will be sent to the doctor who requested your scan, this can sometimes take a few days. Your radiographer will tell you when you can expect to get your results.
An MRI scan is painless and very safe as there are no known side effects from exposure to the magnetic fields or radio waves. Some people may feel claustrophobic, but our experienced team can help you relax.
Potential risks or complications may include:
At Spire Healthcare, we’re careful to weigh up the benefits and risks of any MRI scan and discuss it with you if you have any concerns.
Can you have an MRI scan if you have a metal implant?
You may not be able to have an MRI scan if you have any metal implants or fragments in your body. You should therefore let your healthcare team know if you have any of the below implants:
You should also let your healthcare team know if you have:
An MRI scan captures the details of your tissues differently from other scans. However, in some cases, an alternative scan can be used, such as an arthrography, bone scan, CT scan or ultrasound scan.
How long will an MRI scan take?
An MRI scan can take between 15 to 90 minutes depending on which part of your body needs to be scanned.
I have braces or fillings, should I still undergo an MRI scan?
Braces and fillings are not affected by an MRI scan. You can therefore safely have an MRI scan while wearing braces or if you have fillings. However, they can distort the images produced. Your doctor will discuss this with you. Depending on which part of your body is being scanned, you may need to have more images taken or an alternative type of scan performed.
Can I move while I am in the MRI tunnel?
During your MRI scan, you should not move as this will distort the images captured and you will need to have your scan repeated. However, if you are having a long MRI scan, you can speak to your MRI technician through the two-way intercom to ask for a short break to move around.
I am claustrophobic, what can I do?
You can speak to your doctor before the date of your MRI scan to ask for a sedative on the day — this will help you relax. During your scan, you can talk to your MRI technician through the intercom in the MRI machine to help you feel more comfortable and relaxed. You may also want to wear a sleeping mask so that you don’t have to see the MRI machine around you when you are lying inside it.
Do I need an injection of contrast before my MRI scan?
This will depend on what the MRI scan is being used to investigate and on your health. Your doctor will discuss whether or not you need a contrast agent before your scan.
Can I have an MRI scan if I am pregnant?
MRI scans are not usually recommended for pregnant women. Your doctor may suggest alternative scans, such as an ultrasound scan or CT scan.
What is an MRI scan used to diagnose?
An MRI scan can be used to diagnose a wide range of conditions including:
Which is better, MRI or CT scan?
Both scans produce images of the inside of your body. A CT scan is less expensive and quicker but uses X-rays (a type of ionising radiation). An MRI scan does not use ionising radiation but instead uses radio waves and strong magnets. It can produce more detailed images than a CT scan but is more expensive, takes longer and involves lying down in a tunnel, which some people find claustrophobic.
The type of scan you have will depend on what needs to be investigated in your body. Your doctor will discuss the risks and benefits of each of your scan options and recommend the most appropriate scan.
Is an MRI scan painful?
No, an MRI scan is a painless and safe procedure.
What happens if you move during an MRI?
If you move during your MRI scan, your MRI technician will have to repeat the scan. Scan images can only be captured when you are lying very still.
Can you wear a bra during an MRI?
Yes, you can wear a bra during an MRI scan as long as it does not contain any metal parts eg an underwire.
How do I stay calm during an MRI?
Talking to your MRI technician before and during your scan is a good way to put your mind at ease. During your scan, you can speak to your MRI technician via the two-way intercom. You can also listen to music during your scan through the headphones provided. You may want to slip on a sleeping mask just before you are moved into the tunnel of the MRI machine — this can help if you feel claustrophobic and don’t want to look at the machine around you. Mindfulness techniques can also help, such as focusing on relaxing your body and imagining a light radiating down through your body. If you are very anxious, speak to your doctor before your MRI scan about having a sedative on the day.
The treatment described on this page may be adapted to meet your individual needs, so it's important to follow your healthcare professional's advice and raise any questions that you may have with them.