How magnetic resonance imaging works, what it is best at showing, why it uses no radiation, and how to choose an accredited imaging centre with experienced radiologists.
Written by our medical board, reviewed quarterlyUpdated 21 January 19707 min read
What an MRI scan is and when it's used
Magnetic resonance imaging uses a strong magnetic field and radio waves — not X-rays — to produce highly detailed images of the soft tissues inside the body. Because it involves no ionising radiation, it can be repeated relatively freely and is often the imaging of choice for the brain, spine, joints, muscles and many internal organs.
People book an MRI to investigate a specific concern — persistent joint pain, back problems, neurological symptoms, or to characterise a finding from another test — and sometimes as part of a premium screening programme. Abroad, an MRI is frequently far cheaper than the same scan booked privately at home, with shorter waiting times, which is a common reason patients travel for it.
MRI is exceptional at showing soft tissue but is not always the right tool. For bone detail, lung tissue or acute trauma, a CT scan is often better, and for some questions an ultrasound or X-ray is more appropriate. The right scan depends on the clinical question, ideally decided with a doctor rather than chosen by default.
How the scan works and what to expect
During an MRI you lie still on a table that slides into a tunnel-shaped scanner. The machine is noisy — a series of loud knocking and buzzing sounds is normal — and you are given ear protection. A single scan commonly takes between fifteen and forty-five minutes depending on the body part and the level of detail required, during which staying still is essential for clear images.
Some scans use a contrast agent (gadolinium) injected into a vein to highlight blood vessels, inflammation or tumours. This is generally well tolerated, though the centre will check your kidney function and ask about allergies first. The scan itself is painless aside from the minor discomfort of staying still and, for some, the enclosed space.
If you are claustrophobic, tell the centre in advance: many offer wider, more open scanners or mild sedation. Crucially, MRI involves powerful magnets, so you must declare any metal implants, a pacemaker, or other devices beforehand, as some are unsafe in the scanner.
What it costs
An MRI scan is moderately priced and one of the more cost-sensitive reasons patients travel for imaging. A single-region scan abroad typically falls in the low-to-mid hundreds of euros, often well below the private cost in higher-cost home markets, with contrast-enhanced or multi-region scans costing more.
The price should state whether it covers the scan only or also a radiologist's report, and whether contrast is included if needed. The report is essential — an MRI image is only useful once an experienced radiologist has interpreted it — so confirm that a written report by a qualified specialist is part of the fee.
Check what you receive afterwards: a good centre provides both the written report and the raw images, on disc or via a secure portal, so your own doctor can review them. Imaging without an accessible report and images is of limited value once you are home.
Choosing an accredited imaging centre
Two things determine the quality of an MRI: the scanner and the radiologist who reads it. Modern centres use scanners of at least 1.5 Tesla, with 3 Tesla giving higher resolution for detailed work; either can be excellent in skilled hands. More important is that your images are reported by a board-certified radiologist with relevant subspecialty experience.
Look for centres with international accreditation such as JCI or TEMOS, and ask directly who will interpret your scan and what their qualifications are. A reputable centre will tell you, will provide a clear written report in English, and will not pressure you toward unnecessary additional imaging.
Safety screening is also a marker of quality. A good centre carefully checks for metal implants, devices and contrast allergies before the scan, and explains the procedure clearly. That attention to safety is as important as the technology itself.
After the scan: results and follow-up
An MRI requires no recovery — once the scan is finished you can return to normal activity immediately, and you can usually travel home the same day. If a contrast agent was used, you may be asked to drink extra fluids to help clear it, but there are no restrictions for most people.
The radiologist's report typically follows within a day or two, sometimes sooner. It describes what the images show and flags anything that needs attention. As with all detailed imaging, an MRI may reveal incidental findings — minor, common variations that are harmless but appear because the scan is so sensitive — and a good report puts these in context.
Share the report and the raw images with your own doctor, who can combine them with your history and other tests to decide on any next steps. An MRI answers a specific question; acting on the answer is best coordinated by the team responsible for your ongoing care.
Frequently asked
Is an MRI scan safe?
Yes. MRI uses magnetic fields and radio waves rather than ionising radiation, so it carries no radiation risk and can be repeated as needed. You must, however, declare any metal implants or devices beforehand, as some are unsafe near the magnet.
Does an MRI hurt?
No. The scan is painless; the main considerations are staying still, the loud noise of the machine, and the enclosed space, which some people find uncomfortable. Ear protection is provided.
How long does an MRI take?
Most scans take between fifteen and forty-five minutes depending on the body part and the detail required. Multi-region or contrast-enhanced scans take longer.
What if I am claustrophobic?
Tell the centre in advance. Many offer wider or more open scanners, and mild sedation can be arranged if needed so you can complete the scan comfortably.
When is a CT scan used instead of an MRI?
CT is often preferred for bone detail, lung tissue, and acute trauma, and is faster, while MRI excels at soft tissue such as the brain, spine and joints. The right choice depends on the clinical question.
How soon will I get my results?
A radiologist's report is usually available within a day or two, sometimes sooner. Confirm that the report and the raw images are provided so your own doctor can review them.
