What Happens During an MRI Scan?

During your life you may experience a health problem that has your GP referring you for an MRI, a particular type of scan that allows specialists to better identify certain conditions or health afflictions. In the UK, this can include patients preparing for proton beam therapy or radiotherapy, those who have received injuries to the spinal cord or heart attack sufferers. While undergoing an MRI can be intimidating, by being prepared and well-informed, you can alleviate some of the stress and anxiety that comes from receiving any medical treatment.


What Is An MRI?

MRI or magnetic resonance imaging is the name given to the scan undertaken by an MRI machine, a specialist type of hospital machinery that allows health professionals to produce intricately detailed images from inside the body. The scan works using strong magnetic fields and radio waves and is commonly used to scan areas of the body including the brain, spinal cord, breasts, internal organs, the heart and blood vessels, bones and joints. The scan is carried out by radiographers who are highly trained in offering diagnostic imaging and will be given to radiologists to help plan treatments and see how effective a previous treatment was.


What Happens During an MRI?

Patients that are sent for an MRI may be asked not to eat or drink a few hours before their scan or on some occasions may need to drink a large amount of water beforehand, depending on the area being scanned.

On arrival and after filling out the necessary paperwork, the patient will first be asked to dress in hospital gowns and remove all jewelry, wigs, hearing aids, piercings, watches and foreign objects from their body. If you suspect you have metal in your body or have known implants such as a pacemaker, nerve stimulator, artificial joints or dental fillings, make the hospital staff aware before your scan so they can check for any potential interference or safety concerns.

Some MRI scans will need the patient to be injected with a contrast dye which allows the blood vessels and certain tissues to show up more clearly in images and offer greater detail for diagnosis. Patients may experience some side effects from the contrast dye, including nausea, headaches and dizziness but the side effects are normally short-lived and low intensity. Let staff know ahead of your scan if you have any medical history of blood clotting, allergic reactions or fear of needles so they make the appropriate preparations.

When the patient is ready, they will be asked to lie on a flat bed that will move into the scanner. Dependent on the area to be scanned, the patient will lie either feet or head first to allow the shortest distance of travel and reduce the time the patient needs to be in the scanner. As the scanner generates a strong magnetic field, the patient will be able to communicate with their radiographer via an intercom, where hospital staff will be able to visibly monitor the patient from the next room. Where allowed, a family member or friend can be given permission to accompany the patient in the room during the scan, but they will also be required to report any implants and remove any personal effects and dress suitably with no metallic objects.

The MRI machine can be quite noisy and will emit a series of tapping noises as the coils within the scanner turn on and off, this can be quite overstimulating so patients will be offered earplugs or headphones to protect their hearing and some hospitals can provide calming inputs such as white noise, music or other audio media.

Some scans require a greater amount of detail and the radiographer will use a specially built frame of receivers that when placed over the body part being scanned, receive signals sent out from your body during the procedure and offer more intricately detailed imaging for diagnosis.

It’s important for the patient to remain still for the procedure however scans do not normally last long enough to offer sedation unless the patient suffers from extreme claustrophobia. Scans will often last between 15 to 90 minutes depending on where the scan is, how many images need to be taken and the size of the area to scan. Sufferers of acute claustrophobia will be offered additional support where necessary from their radiographer and should let their doctor know when being referred for an MRI scan. Remaining still will ensure optimal detail from the scan, allowing a quick and clear diagnosis where possible and reduce the need for additional scans. Patients who are offered a sedative will need to be monitored for 24 hours afterwards by family or friends and will need to be driven home afterwards once the sedative has worn off.

Babies and young children will normally be given a general anaesthetic before undergoing an MRI scan as they commonly struggle with lying still for longer periods of time and can lengthen the time the procedure takes.


Are MRIs Safe?

Extensive studies have been carried out to ensure the safety of MRI scans and are generally recognized as one of the safest medical procedures a patient may need to undergo during the diagnosis or treatment process.

There is no need to be concerned about an MRI scan, it is perfectly harmless and without sedation, you can continue on with your day as normal, going about daily activities. Hopefully this guide has helped reduce any fears you may have regarding an upcoming MRI or assisted in learning about the MRI process. Talk to your doctor if you have any further concerns or questions you need answered.



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Written by HealthStatus Crew
Medical Writer & Editor

HealthStatus teams with authors from organizations to share interesting ideas, products and new health information to our readers.

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