Anesthesia for MRI Patient Education

Pre-Procedure Patient Information

What is anesthesia and when is it used with MRI?

Aesthesia is the use of medicines to make a person “relax” or “go to sleep.”  Anesthesia is used with MRI if the patient is unable to be still for the length of the scan or if the patient has severe claustrophobia.

What conditions should I make sure my doctor is aware of?

Before your exam, you should notify the anesthesiologist or nurse if you:

  • Have had a previous reaction to contrast used in MRI
  • Have any drug/food allergies
  • Any problems you or family members have had with sedatives and anesthetic medicines
  • Any medical conditions you have
  • Whether you are pregnant or may be pregnant

What are the risks of anesthesia?

Generally, anesthesia is safe. However, problems may occur, including:

  • Allergic reaction to anesthetics
  • Lung and heart problems
  • Inhaling food or liquids from your stomach into your lungs (aspiration)
  • Injury to nerves
  • Waking up during your scan and being unable to move (rare)
  • Extreme agitation or a state of mental confusion (delirium) when you wake up from the anesthetic.

These problems are more likely to develop if you have an advanced medical condition. You can prevent some of these complications by answering all of your health care provider’s questions thoroughly and by following all pre-procedure instructions.

General anesthesia can cause side effects, including:

  • Nausea or vomiting
  • A sore throat from the breathing tube
  • Feeling cold or shivery
  • Feeling tired, washed out, or achy
  • Sleepiness or drowsiness
  • Confusion or agitation
  • Mental slowness

About the Procedure

Before the test:

  • Do not eat or drink anything for 8 hours before your MRI appointment.
  • If you have diabetes and use insulin, you may need to adjust the dosage of insulin the night prior and the day of the MRI. Your primary care doctor can help you with this adjustment.
  • Do not discontinue any medication without first consulting with your primary care or referring physician.
  • Do not take new dietary supplements or medicines during the week before your MRI unless your health care provider approves them.
  • Plan to have someone take you home and stay with you for the first 24 hours after you leave the hospital. You should not drive or operate heavy machinery for at least 24 hours after the procedure.
  • You may have blood tests done to show how well your kidneys are working

The day of the test:

  • If you were told to take a medication or to continue taking a medication on the day of the procedure, take the medicine with a small sip of water.
  • Please arrive and register at admissions in the lobby of the hospital at your scheduled time.
  • You will be escorted to the prep area, where you will be connected to a blood pressure machine that will take your blood pressure and your heart rate. You will also have electrocardiogram (ECG) leads placed on your chest.
  • A nurse will insert an IV into your arm. During the MRI, this IV will be used to give you medications and possibly contrast dye, which is used to enhance the visibility of certain tissues.
  • A nurse will review your medical history and medications, listen to your heart and lungs and make sure you have followed all your pre-procedure instructions.
  • You will meet the anesthesiologist and they will obtain your consent for anesthesia prior to the MRI. They will explain possible complications and side effects. They will also answer any questions you may have.

During the test:

You will be given medications through your IV and/or a mask. These medications will help you relax and/or fall asleep. As soon as you are asleep, a breathing tube may be used to help you breathe.

An anesthesiologist will stay with you throughout the scan. They will help keep you comfortable and safe by adjusting the amount of medicine that you get. They will also watch your blood pressure, pulse, and oxygen levels to make sure that the anesthetics do not cause any problems.

If a breathing tube was used to help you breathe, it will be removed before you wake up.

After the test:

  • You will wake up, often slowly, after the procedure is complete, and will go to the Post Anesthesia Care Unit (PACU).
  • Your blood pressure, heart rate, breathing rate, and blood oxygen level will be monitored until the medicines you were given have worn off.
  • You may be given medicine to help you calm down if you feel anxious or agitated. Your health care providers will treat any side effects before you go home.
  • You will then return to the area where you were before the MRI scan. Prior to going home, your nurse may check to make sure you can stand, drink and urinate.
  • You will then be discharged home. Do not drive for 24 hours after anesthesia. Plan to have someone take you home and stay with you for the first 24 hours after you leave the hospital.

Who interprets the results and how do I get them?

The radiologist will interpret your study results. Because the images require time to process, the results are not available immediately. Final results will be sent to the physician who ordered your test within a few days. The results will also be sent to your My Chart account.

Contact Information

Please contact your ordering provider with questions or concerns.

Get help right away if:

  • You are short of breath or have trouble breathing
  • You have chest pain

These symptoms may be an emergency. Get help right away. Call 911.

  • Do not wait to see if the symptoms will go away.
  • Do not drive yourself to the hospital.