If you have a persistent medical issue you want to get to the bottom of, you might have heard of an MRI. But just what is an MRI scan? MRIs create detailed images of inside the body and can give you an accurate view of what’s going on under the hood. So, if you’re struggling with persistent pain, an MRI might hold the key to diagnosing the issue.
Join us as we look at the science, side effects, and costs of having an MRI scan.
So, let’s kick off with the basics: what does MRI actually stand for? Well, MRI stands for ‘Magnetic Resonance Imaging’. It might sound technical but it simply refers to the magnetic and radio waves used in the scanning process.
During an MRI scan, the body part being scanned is aligned with a magnetic field created by the scanning machine. Radio waves are then generated and the combination causes the body’s atoms to release signals. These are then translated into images.
How is an MRI different from other scans?
The main difference between an MRI scan and others such as CT scans and X-rays is the use of magnetic waves. While CT scans and X-rays use radiation to create images, an MRI scanner uses magnetic and radio waves.
Other differences include:
the ability to generate better image detail when it comes to soft tissue
no risks associated with using radiation.
Who might need an MRI scan?
An MRI scan is used to provide detailed imagery of soft tissues, the brain, spine, nervous system, joints, and internal organs.
With that in mind, the following people might need an MRI scan:
A patient with an ongoing condition that requires monitoring
A patient with unexplained pain or symptoms.
A doctor needing more detailed information about a patient’s specific condition that X-rays and CT scans can’t provide.
How does an MRI scan work?
We’ve looked at the differences between MRI and other scans, and the type of people that might need one. Now it’s time to answer the question: how does an MRI work?
This is going to sound like a line out of a Star Trek episode but bear with us! An MRI scan works by creating a strong magnetic field that focuses the atoms within a specific body part (the one being scanned!). The MRI machine then releases radio waves that jostle and push the atoms around. As these atoms return to their original alignment, (at different speeds) they release signals that MRI technology, in all its sci-fi brilliance, is able to translate into imagery!
What does an MRI machine look like?
The MRI scanner itself looks a bit like a tunnel that’s open at both ends. The patient lies on a long moveable table that slides them into the circular part of the scanner. This is where the imaging takes place.
MRI machines emit loud noise, and it’s not uncommon for patients to listen to music or a podcast while the machine is at work.
What are the different types of MRI machines?
Closed – this is the standard MRI scanner. It features a narrow tube (usually about 60cm wide) which the patient slides into for the imaging to take place. These typically offer high-quality images
Open – this MRI scanner is open-sided and more often than not, the patient is only slid in halfway. It was designed to be more comfortable for the patient but doesn’t provide the same level of image detail as the closed MRIs
Standing – sometimes called an ‘upright imaging MRI’, this type provides more flexibility for the patient as it allows for scanning in numerous positions. This type of scan can diagnose certain issues faster than a traditional MRI and is more comfortable for larger patients
Extremity MRI – designed to create images of arms, legs, hands, and feet, this type of MRI scanner is much smaller than the others. Capable of generating high-quality images, an extremity scanner allows for more patient comfort and creates less noise than a traditional MRI. The one major drawback is its size; it’s only capable of scanning smaller body parts. Patients with head, neck, or back issues will need to use one of the other MRI scanners.
MRI vs CT scan: what’s the difference?
While both types of scan create images of the internal body to help diagnose a range of different medical conditions, the main difference between a CT scan and an MRI is the former uses X-rays, while an MRI uses strong magnetic fields to create images.
CT scans are often used in emergency situations (fractures and broken bones) as they produce faster results. As MRI scans are considered to provide more accurate imagery, they’re used to diagnose conditions associated with bones, internal organs, and joints.
What happens during an MRI scan? (procedure and patient experience)
So, you’re all booked in for your MRI scan and the time has come. What can you expect? Well, you’ll first need to complete and sign a safety questionnaire to make sure it’s safe for you to go into the scanner. It’s important to remember to stay calm and as relaxed as possible. This will help keep you still while the machine takes images.
To start the MRI scan procedure, you’ll be asked to lie down on a bed that will then slowly and automatically slide into the MRI scanner. The radiographer will leave the room once you are in the scanner, but don’t worry, they’ll be in touch with you for the entirety of the MRI scan procedure via an intercom.
Depending on what you’re having scanned, the entire MRI experience could take around an hour to complete.
Before your MRI: how to prepare
If you’ve been sent a safety questionnaire by the booking team, please take some time to fill it in. If you have answered any questions ‘Yes’ you should contact the booking team to notify them. Don’t worry if you haven’t been sent a safety questionnaire, we’ll have one waiting for you when you arrive for your scan.
On the day of your scan, don’t forget to bring the questionnaire and dress in clothes with no metal (i.e. zips, buttons, jewellery etc).
What to expect during your scan
During the scan, it’s important to lie as still as possible so the machine can capture detailed images. If, at any point, you need to stop the scan, squeeze the buzzer you’ll be given before you enter the machine. This will allow you to speak to the radiographer. The scanner is very noisy – this is due to the electrical current passing through the components of the machine. Don’t worry though, this is completely normal and you’ll be given earplugs and headphones to help dampen the noise.
After the scan: getting your results
The scans will be read by a radiologist and the results will go back to your referrer. This usually takes around three working days. Your referrer will discuss the results with you at your next appointment. If you are a self-pay patient you will also get a copy of the results.
“With Wellsoon I was able to book straight in for the (MRI) scan. It was very simple…based on the results I knew not to push through (with running the marathon) and make things worse.”
Megan Riley, MRI scan patient at Practice Plus Group MSK and Diagnostics, Buckinghamshire
When it comes to safety, MRI scans are second-to-none. According to the NHS,1 numerous studies and investigations over the years support that MRI pose minimal risk to patients.
Who should not have an MRI?
There are certain situations where an MRI scan might not be suitable. For example, those with implanted devices (e.g. cochlear implants, and pacemakers) or metallic foreign bodies. MRI safety may also be called into question for pregnant women. This is because the side effects of magnetic fields on unborn babies are currently unknown.
Are there any side effects?
For a small number of MRI scans, a contrast agent is used. In rare cases, patients may react negatively. Allergic reactions are typically mild and may include a rash, itching, dizziness, headaches, and fatigue.
The side effects of magnetic fields on unborn children are unknown. For this reason, pregnant women are often not seen as good candidates for an MRI scan, particularly in the first trimester of pregnancy.
Waiting times for an MRI scan
If you’re seeking an MRI with the NHS, the national target is under six weeks for GP referred patients. If you’re a private patient at Practice Plus Group MSK and Diagnostics, Buckinghamshire, you’ll be able to have your scan within a few days of booking. Please note, waiting times at other Practice Plus Group hospitals may vary.
Who will perform my MRI scan?
Your MRI scan will be carried out by a team of highly trained and skilled radiographers.
How much does an MRI scan cost in the UK?
The average cost of a private MRI scan in the UK is typically anywhere between £200 – £1,500. This can be higher if more than one body part needs to be scanned. According to Get Scanned UK,2 the average cost of a private MRI scan for one body part is around £395.
Prices can vary depending on the following factors:
UK location
The type of scan needed
The clinic or hospital chosen to carry out the scan.
At Wellsoon from Practice Plus Group, an MRI scan for one body part costs £334.
Not yet found the information you’re looking for? Our dedicated MRI scan FAQs may well be able to help!
What are the side effects of an MRI?
There are no known direct side effects of the MRI scan itself. In rare cases, patients may react negatively to the contrast agent taken before the scan. The side effects of this can include dizziness, headaches, and fatigue.
The side effects of magnetic fields on unborn children are unknown. For this reason, pregnant women are often not seen as good candidates for an MRI scan.
How long does it take for an MRI to scan your entire body?
It’s highly unlikely you’ll have an MRI scan for your entire body. MRI scans typically focus on one specific area. This can be the neck, back, head, arms, or leg. The scan time for a single body part ranges from 10-20 minutes.
Do MRI scans hurt?
No, MRI scans do not hurt. If, at any point, you’re feeling uncomfortable during the scan, please let your radiographer know via the intercom.
Why are MRI scans so noisy?
The noise from the MRI machine is caused by electricity passing through the coils within the magnets. These coils vibrate strongly in the process of the machine creating a magnetic field which results in the noise.
What can I wear during an MRI scan?
Try to avoid wearing clothes with too much metal e.g. zips and buttons. You’ll need to remove jewellery and piercings too.
Can I have an MRI with claustrophobia?
Yes. If you suffer from claustrophobia or are anxious about the MRI scan, just let your radiographer know. He or she may be able to administer a sedative to relax you for the procedure.
What is the difference between MRI and CT scan?
MRI scans produce images of the internal body using magnetic and radio waves while CT scans use X-rays.
CT scans are also more likely to be used to produce imagery in emergencies such as broken bones, fractures, or for diagnosing a stroke.
Are there risks with MRI contrast dye?
Occasionally, some patients can experience side effects from the contrast agent used in MRI scans. These can include fatigue, headaches, and dizziness.
Can I have an MRI if I’m pregnant?
It isn’t recommended. This is because the effects of strong magnetic fields on unborn babies are not yet known.
Kerry qualified as a radiographer from Kingston University in 2001. She continued her training at Kings College London and gained her Pg Dip in Diagnostic Ultrasound in 2003.
After working extensively in the NHS Kerry joined PPG in 2013. Kerry has continued to develop her breadth of skills and completed her PgCert in MSK ultrasound in 2020. Kerry performs a wide range of scans including Gynae, Abdominal and MSK ultrasound.
In 2023 Kerry took on the role of Diagnostic Clinical Lead and she looks forward to the challenge of leading the clinical team, ensuring demand of the diagnostic service is met, whilst maintaining smooth running of the patient journey along with scanning ultrasound patients in clinic.
