Your questions about MRI scans answered
MRI scanning uses powerful magnets to create a detailed image of the inside of your body to help doctors diagnose conditions and plan your tailored treatment – but how does it work and what is involved?
MRI machines are usually controlled by radiographers, who are allied health professionals that carry out your scan and operate the equipment. They are specially trained in operating diagnostic medical equipment, and as well as MRIs they’ll perform tests such as X-Rays and CT scans.
Your radiologist, a doctor, will interpret the results of your MRI scan and make a diagnosis of your condition. They might also be involved in building your treatment plan, but this depends on your individual circumstances.
We understand that the prospect of having an MRI scan can seem a bit daunting, especially for people who are claustrophobic and don’t like enclosed spaces – but the more you understand about MRIs and how safe they are, the better you might feel about them.
Are you having an MRI scan soon? We’ve shared everything you need to know about MRI scans below to help you feel that bit more informed before yours.
An MRI is a very powerful and effective diagnostic tool that provides detailed, cross-sectional images of the body.
What does an MRI scan show?
An MRI scan is often the first step in diagnosing heart disorders and orthopaedic issues, such as broken bones, torn ligaments, and arthritis.
MRI machines are particularly good at imaging soft tissues in your body, including your brain, spinal cord, muscles, tendons, ligaments, and organs like your liver, kidneys, and heart. The scan can reveal abnormalities, tumours, inflammation, and structural problems in these tissues. It can also detect tumours, aneurysms, strokes, multiple sclerosis lesions, and other neurological conditions. MRI can also detect herniated discs, and conditions like osteoporosis.
Overall, an MRI is a very powerful and effective diagnostic tool that provides detailed, cross-sectional images of the body, enabling your doctor to make accurate diagnoses and guiding them towards the best treatment plans for a wide range of medical conditions.
How do MRI scans work?
An MRI scanner uses strong magnets and radio waves and can examine almost any part of your body to produce a detailed cross-section image.
Each of the atoms in your body is highly sensitive to magnetic force. The strong magnets in an MRI scanner make all the atoms in your body line up in the same direction. The scanner then sends short bursts of radio waves to knock the atoms out of alignment before the magnet pulls them back into line again. As the atoms realign, they send out a radio signal, showing exactly where they are in your body.
In an MRI scan the atoms in your body behave like the pixels on a computer screen. There are millions of atoms sending millions of signals, and the atoms of each type of tissue in your body produce a different signal. These signals show up as the different elements of a detailed image.
What is the difference between an MRI and a CT scan?
CT scans and MRI scans have similar functions, but they produce images of the inside of your body in different ways. A CT scan uses X-rays, while an MRI scan uses strong magnetic fields and radio waves. They are both used to diagnose and monitor a range of conditions.
The key differences between CT scans and MRI scans include:
- CT scans use radiation, which is associated with medical complications such as infection and sickness. However, the levels of radiation you are exposed to during a CT scan are extremely low, which is why this form of testing is perfectly safe
- CT scans are generally faster than MRI scans, taking between 10 and 20 minutes, while MRI scans usually take up to 90
- CT scans are quiet, while MRI scans are very noisy. You will be offered earplugs during an MRI scan to block out the noise, though, so you won’t hear much
- CT scans are not enclosed spaces; the machine rotates around you. An MRI scanner is a large, tube-like, enclosed machine
What does an MRI look like?
An MRI machine typically looks like a large, hollow cylinder or tube. It is often surrounded by a circular, tunnel-like structure. The size of MRI machines can vary, but some can be quite roomy, while others are more compact. The part you'll lie down on will typically be a movable table that slides into the tunnel. The outer part of the machine is made of a strong, round magnet, and there's a lot of complex technology working to generate the images inside.
You might also notice a control room nearby where a radiographer or radiologist operates the machine and monitors the scan. Some MRI machines are designed to be larger, which can be helpful for people who might feel claustrophobic in the traditional tunnel-like setup. So, the appearance of an MRI machine can vary a bit depending on the specific model and design.
How long does an MRI scan take?
The length of an MRI scan can vary depending on what your doctor is looking for and where in your body they are looking for it. On average, though, you can expect an MRI to take anywhere from 20 minutes to an hour. For example, if you're getting your knee scanned, it might be on the shorter end of that range. But if you are having a more comprehensive study, such as a full-body MRI, it can take longer.
Is an MRI scan painful?
The procedure is painless! It is also completely safe. There has been no evidence to suggest an MRI scan is unsafe, making it one of the safest diagnostic procedures available.
How much is an MRI privately?
The cost of an MRI varies depending on why you have the scan, where you have it, and which part of your body is being scanned. You'll find more information here about the cost of private MRI scans with Circle Health Group.
What happens during an MRI scan?
An MRI scan usually takes between 15 and 90 minutes, depending on how much of your body is being scanned. You will lie on a flat bed, which slides into the tube-shaped MRI scanner. You may go into the scanner headfirst or feet first, depending on which part of your body is being scanned.
It’s very important to keep as still as you can while the scanner is working so that the image is as accurate as possible. You will be given headphones or earplugs to wear, as the MRI scanner makes occasional loud tapping noises when the electric current switches on and off.
Your MRI scan will be carried out by a highly trained radiographer, who controls the scanner from another room using a computer. They will be able to see you on a TV monitor to keep an eye on you throughout the scan, and you’ll be able to speak to them from the scanner via an intercom.
The reason MRI scanning is so safe is that it does not use X-Rays, meaning you are not exposed to any potentially harmful radiation.
Are MRI scans safe?
Yes! As mentioned above, MRI scanning is one of the safest imaging techniques there is. It is also painless, although if you have claustrophobia, you might find going into the scanner slightly uncomfortable. Your radiographer will be accustomed to helping people deal with claustrophobia and can support you throughout the scan. Many people are offered distractions like music, or in some cases can even watch a small TV inside the MRI scanner, to alleviate symptoms of claustrophobia.
The reason MRI scanning is so safe is that it does not use X-Rays, meaning you are not exposed to any potentially harmful radiation. Some people are particularly vulnerable to the effects of radiation, such as pregnant women and babies, and these people are often recommended for MRI scanning.
There has been a great deal of research into whether there is any risk to the human body from the magnetic fields and radio waves used for MRI scanning. There is no evidence to suggest that there is any risk at all to your body and MRI scanning is actually one of the safest medical procedures available.
Is MRI scanning suitable for everyone?
MRI scanning is suitable for the vast majority of people, but if you have certain implants fitted, an MRI scan may not be safe for you. This includes pacemakers, which are battery-operated devices helping to control an irregular heartbeat.
What is a contrast agent for an MRI?
A contrast agent for an MRI is a substance used to enhance the visibility and contrast of certain structures or abnormalities in the images produced. These agents contain a paramagnetic substance, most commonly gadolinium, which affects the magnetic properties of nearby tissues.
The contrast agent is typically injected into a vein in your arm or hand using a small needle and a syringe. In some cases, it might be administered orally, depending on the specific area of your body being imaged.
Once in your bloodstream, the contrast agent circulates through your body and accumulates in specific tissues or areas of interest. It alters the magnetic properties of these tissues, making them appear brighter or darker on the MRI images. This is especially useful in highlighting blood vessels, tumours, areas of inflammation, and abnormalities in your brain, spinal cord, or other organs.
Getting an MRI with Circle Health Group
We hope this information has helped you feel more comfortable and informed about having an MRI scan.
At Circle Health Group we offer private MRI and CT scans performed by dedicated specialists. If you have been told you need an MRI scan, call us directly and we’ll help you arrange one (you’ll need a letter of reference). If you think you need an MRI scan but don’t have a referral yet, you can book online with one of our specialists who will be able to help you get the right scans for you, or you can call us for further advice.
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How do I book an appointment?
If you're concerned about symptoms you're experiencing or require further information on this subject, talk to a GP or see an expert consultant at your local Circle Hospital.