6 Things to Know About Having an MRI

  • Doctor Preparing Patient for MRI
    MRI: From Head to Toe
    Magnetic resonance imaging, MRI for short, is a noninvasive test that produces a very detailed image of tissues inside your body. MRI is both painless and safe. Most importantly, it can give your doctor valuable information about problems anywhere from your brain to your feet. So, your doctor might order an MRI to diagnose an ailment in your head, chest, abdomen, pelvis, legs, arms or blood vessels. Get the facts on how MRI works and what to expect.

  • MRI scan result of knee on computer monitor
    1. There are no X-rays in MRI.
    That means there's no danger from radiation. Instead, MRI creates images using a combination of a magnetic field, radio waves and a computer. As you lie on an exam table, the MRI machine sends radio waves through your body. This causes energy changes. The equipment measures the changes and turns them into images. Often, MRI creates a better image than other common tests like an X-ray, CT scan or ultrasound.

  • Doctor reviewing chart of patient about to have MRI scan
    2. Metal inside your body can be a problem.
    Because MRI uses strong magnets, it can move metal inside your body. Let your doctor know if you have any type of metal implant. Your doctor also needs to know if you have a bullet or metal fragment somewhere in your body. MRI also can damage metal or electric medical devices like pacemakers and hearing aids. Some medical devices are compatible with MRI and you should get an ID card stating it as such. Before your MRI, your MRI technologist will go over all the possible metallic or electric objects that could be a problem. Make sure to leave all your jewelry at home.

  • Doctors preparing patient for MRI scan
    3. You may need an injection with your MRI.
    Using a contrast material called gadolinium may improve the MRI images for some conditions. You'll get gadolinium through an intravenous (IV) line in your arm or hand. Ask your doctor in advance if you'll need contrast for your exam. Gadolinium can cause kidney damage in rare cases, so be sure to tell your doctor if you have a history of kidney disease.

  • patient receiving an MRI scan
    4. MRI is loud.
    An MRI is painless, but it's definitely loud. A movable exam table will glide you into the MRI machine. The machine takes several images. It may take a few minutes to take each one. During these times, you'll hear loud tapping and thumping. You might want to wear earplugs or headphones. They'll help block out the sounds and protect your hearing. 

  • Patient about to have MRI examination
    5. MRI can be a long and tight squeeze.
    With a traditional MRI, your body slides into a tight tube. You will have enough room to breathe. But, you'll need to stay silent many times during the procedure. The entire process may last up to an hour or two. If you have a fear of closed spaces, you may be very uncomfortable. Sometimes you can get medication to make you relaxed and sleepy. Or, ask your doctor if an open MRI is available. These scanners do not wrap around your whole body.

  • Nurse helping patient in hospital
    6. Tell your doctor if you are or may be pregnant or are breastfeeding.
    There's no evidence an MRI can harm a baby inside your womb, but your doctor will likely have you avoid taking this test during the first three months of your pregnancy. After three months, your doctor will decide if MRI is worth any risk. You should not have an MRI with contrast at any time during pregnancy. If you're breastfeeding, you can have MRI and contrast, but you should not breastfeed for 24 hours after the scan.

6 Things to Know About Having an MRI

About The Author

  1. Magnetic Resonance Imaging (MRI) -- Body. Radiological Society of North America. http://www.radiologyinfo.org/en/info.cfm?pg=bodymr
  2. Magnetic Resonance Imaging (MRI) Safety. Radiological Society of North America. http://www.radiologyinfo.org/en/info.cfm?pg=safety-mr
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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Sep 3
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.