Health Topic

MRI Scans

Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside the body. Read about the use of MRI scan.

Reviewed Reviewed by a registered pharmacistGeneral information

Also called: Magnetic resonance imaging · NMR · Nuclear magnetic resonance

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About MRI Scans

Magnetic resonance imaging (MRI) is an imaging test that is usually painless and uses magnets, radio waves, and a computer to create detailed pictures of the inside of your body. MRI scans show organs and soft tissues clearly and can help tell healthy from unhealthy tissue in many cases.

MRI scans are often used to diagnose conditions that affect soft tissues and to monitor treatment.

MRI may be used to look at:

  • The brain, spinal cord, and nerves
  • Muscles, ligaments, and tendons
  • Joints, such as the knee or shoulder

MRI does not use x-rays or other radiation. Because of this, it may be used when repeat imaging is needed.

MRI machines use powerful magnets. Metal objects or implants can interfere with the scan and may be unsafe.

Before your MRI, you will need to remove items such as:

  • Jewelry and watches
  • Hairpins
  • Hearing aids

Before your MRI, tell your health care provider if you:

  • Are pregnant
  • Are breastfeeding, especially if you may receive contrast material (a substance that helps some parts of your body show up more clearly on the images)
  • Feel anxious in enclosed spaces (claustrophobic)
  • Have kidney problems
  • Have metal in your body, such as bullets, shrapnel, or other metal fragments
  • Have metal or electronic devices in your body, such as a pacemaker, artificial joint, or other implants
  • Have tattoos or permanent makeup, since some darker inks may contain metal

You will usually change into a hospital gown. Sometimes before the test, you may receive contrast, which is usually given through a vein (intravenously or IV).

During the scan, you lie on a table that slides inside a large, tunnel-like machine. Some facilities use an open MRI machine, which is less enclosed. The machine makes loud noises as it takes pictures. You may be given earplugs or headphones.

The scan can take some time, depending on the part of your body being examined. You will need to stay very still during the scan.

After most MRI scans, you can return to normal activities right away. If you were given medicine to help you relax, someone will need to take you home.

A specialist called a radiologist reviews the images and shares them with your provider.

It sits within Diagnostic Tests.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on MRI Scans

228 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

Start Here

Related Issues

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Magnetic Resonance Imaging. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for MRI Scans, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.