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Magnetic Resonance Imaging

What you should know

A magnetic resonance (REZ-oh-nans) imaging scan is also called an MRI, a nuclear magnetic resonance (NMR) or a magnetic field scan. It is a medical test used to take pictures of the inside of the body. Each picture or "slice" shows only a few layers of body tissue at a time. The MRI machine uses a large magnet, and a computer to make pictures of your body. Pictures taken this way may help caregivers find and see problems in the body more easily. This test usually takes between 15 and 90 minutes.

Picture of a Magnetic Resonance Imaging closed machine

Care Agreement

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.


Having an MRI is very safe. Risks only apply if you have a metal device in your body, which would prevent you from having the test. You also should not have an MRI during the first three months of pregnancy. You may have trouble being inside the machine if you are claustrophobic (afraid of closed spaces). Caregivers may give you medicine to help you relax. Call your caregiver if you are worried or have questions about having an MRI.

Getting Ready


Do not eat solid food four to eight hours before the test if you're getting dye or sedative (SED-ah-tiv) medicine during the test. You may have clear liquids up to two hours before your exam. Clear liquids include water, black coffee or tea, apple juice, clear soda, or clear broth. Follow any other special instructions from your caregiver.


Do not wear any jewelry including rings, earrings, necklaces, or watches. Take off anything metal that is on your body. Also, take off any clothing that has metal hooks, buttons, zippers, or other metal items on it.


  • Informed consent: You have the right to understand your health condition in words that you know. You should be told what tests, treatments, or procedures may be done to treat your condition. Your doctor should also tell you about the risks and benefits of each treatment. You may be asked to sign a consent form that gives caregivers permission to do certain tests, treatments, or procedures. If you are unable to give your consent, someone who has permission can sign this form for you. A consent form is a legal piece of paper that tells exactly what will be done to you. Before giving your consent, make sure all your questions have been answered so that you understand what may happen.
  • Screening Sheet: You will be asked to fill out a screening sheet. Tell your caregiver if:
    • You have any metal in your body, such as metal screws, pins, or plates.
    • You have a medication patch on your skin. Some medication patches have metal in or on them. This could lead to a skin burn during an MRI. Examples of medication patches are nicotine, birth control, or nitroglycerin patches. Ask if your patch should be off your skin during the MRI.
    • You think you are pregnant. The MRI should not be done during the first three months of pregnancy. Your caregiver needs to know so he can decide whether you should have the test.
    • You are claustrophobic (klaws-troh-FOH-bik) or afraid of being in closed or cramped places. Your caregiver may then give you sedative medicine to help you relax during the test. You must not eat solid food for four to eight hours prior to your sedation. You will also need an adult to driver you home if you have a sedative.


Bring a family member or friend with you if you need to wait for test results. They can talk with you and be there to support you during and after the test. They can also drive you home if you have sedative medicine during the test.

Test information:

  • Write down the correct date, time, and location of your procedure.


What Will Happen:

  • You will be asked to change into a hospital gown and to remove all jewelry, earrings, or other metal objects. Caregivers will help you lie down on the MRI table. The body part being tested may be kept in place with a cradle or straps to hold it very still. You must lie very still during the test. The MRI pictures may not be clear if you move even a small amount.
  • An IV may be put in a vein in your hand or arm. Dye may be put through the IV to help body parts show up better in the MRI pictures. Your skin around the IV may feel warm or cold as the dye is put into the IV. Tell your caregiver if you feel unusual as the dye is given. Tell your caregiver if you are allergic to shellfish (lobster, crab, or shrimp), as you also may be allergic to this dye.
  • Sedative medicine may also be given through this IV to help you relax. Your caregiver will then take your vital signs during the test. This includes taking your temperature, blood pressure, pulse (counting your heartbeat), respirations (counting your breaths) and pulse oximetry (ok-SIM-e-tree). To take your blood pressure, a cuff is put on your arm and tightened. The cuff is attached to a machine, which gives your blood pressure reading. Caregivers may listen to your heart and lungs by using a stethoscope (STETH-oh-skohp). The pulse oximeter machine tells how much oxygen is in your blood. A cord with a clip or sticky strip is put on your ear, finger, or toe and hooked to the machine. Readings on this machine tell caregivers if you need more oxygen.
  • When the test starts, the table will move into a narrow tunnel in the machine. As the machine takes pictures, it is very noisy. It may sound like loud hammering or grinding metal as the magnets move in the machine. Your caregiver will tell you when the test is finished.

Waiting Room:

Ask your caregiver if you want a family member to remain with you during the test. Your family may also wait for you in the waiting room until your MRI is done. If your family leaves, ask them for a phone number where they can be reached.

Contact a caregiver if

  • You cannot make it to your MRI appointment on time.
  • The problems for which you are having an MRI get worse.
  • You have questions or concerns about having an MRI.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.