Quick version
Summary – how MRI really works
MRI (magnetic resonance imaging) is a modern diagnostic imaging test that is used to take detailed pictures of the inside of the body without using ionizing radiation. Although MRI is a safe and well-established method, there are several common misconceptions about the test, including radiation, pain, metal in the body and how long the test takes.
An MRI test is painless, non-invasive and is used in many medical fields – not just for serious illnesses. For most people, the test takes between 15 and 60 minutes, and in many cases, everyday life can continue as usual immediately afterwards. By knowing what is myth and what is fact, you can feel more confident about a possible MRI test.
- MRI involves dangerous radiation: No, MRI does not use ionizing radiation.
- Metal in the body stops MRI: Not always – many implants are MRI compatible.
- MRI hurts: It is a painless examination.
- MRI is only for serious diseases: MRI is used in many different medical contexts.
- MRI takes forever: It usually takes 15–60 minutes.
Magnetic resonance imaging (MRI) is one of the most advanced and useful imaging techniques in modern medicine. Despite the fact that the technology is used daily in hospitals and clinics, there are many misconceptions about how the test works, whether it is dangerous, and what it can detect.
In this article, we debunk five common myths about MRI scans and explain what is true.
1. “MRI scans use dangerous radiation”
Facts: MRI scans do not use ionizing radiation like X-rays or CT scans. Instead, they use a strong magnetic field and radio waves to create detailed images of the body’s soft tissues.
Because MRI does not involve radiation, it is a safer test for people who need repeated tests, such as for chronic disease monitoring.
2. “You can’t have an MRI if you have metal in your body”
Facts: Although the MRI machine has a strong magnetic field, not all types of metal are an obstacle. Most of today’s modern medical implants (e.g. pacemakers or joint replacements) are designed to be MRI-compatible.
It is of course of utmost importance to always tell us if you have metal in your body before the examination. This will allow the staff to decide whether a safe MRI examination is possible or whether alternative imaging diagnostics should be used.
3. “MRI examinations are painful and uncomfortable”
Facts: An MRI examination is non-invasive and completely painless. You lie still (you should lie still) on a table while the machine takes images. You will certainly experience noisy sounds and sometimes feel a little uncomfortable from lying still, but it does not hurt.
Tip: To make the examination more comfortable, you are often given hearing protection or music via headphones during the examination.
4. "MRI is only performed when serious diseases are suspected"
Facts: The method is used for many different types of medical examinations, not only for serious diagnoses. It is an important tool for prevention, but of course also for examining everything from joint injuries and back problems, tumors, blood vessel changes and neurological conditions.
Example: Doctors may order an MRI to better understand the cause of pain, swelling or to follow up on previous findings - even if there is no suspected serious diagnosis initially.
5. “MRI takes a very long time and is impractical”
Facts: A typical MRI scan usually takes 15–30 minutes. The time varies depending on the area(s) being examined. Preparation is usually simple and you can usually return to normal activities immediately afterwards.
Patient information: Your referring doctor and staff involved in the examination should give you clear instructions both before and after the examination. This includes everything from whether you need to change clothes, remove metal objects or if any special preparations are required.