Magnetic Resonance Imaging (MRI) of Your Prostate

This information will help you prepare for magnetic resonance imaging (MRI) of your prostate.

An MRI is a procedure that uses strong magnetic fields to produce pictures of the inside of your body. It is used to detect the type, size, and location of tumors. It is also used to check your response to treatment. Your MRI will take 30 to 45 minutes.

Rectal Coil

As part of your MRI, your doctor may have you use a rectal coil to increase the detail of the images. The coil is a small, flexible plastic tube that is gently inserted into the rectum by a nurse or doctor. It feels a lot like having a digital rectal exam. After the coil is placed, a balloon is inflated to help hold it in place during the exam. The balloon is deflated and the coil is taken out at the end of the exam.

Some people cannot have a rectal coil exam. You may not be able to have the exam if you:
  • Have large hemorrhoids
  • Had pelvic surgery within the past 8 weeks
  • Had radiation therapy to your prostate or pelvis within the past 6 months
  • Have any disease of your rectum
  • Have bleeding from your rectum
  • Have a latex allergy
  • Have inflammatory bowel disease

If your technologist or radiology nurse thinks the rectal coil exam will not be possible, he or she will discuss it with you.

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Preparing for Your MRI

  • If you have a medical implant or device, ask the doctor who put it in for the exact name and manufacturer. If you don’t have this information before your MRI, you may not be able to have it that day.
  • If it is hard for you to lie still for about 1 hour, or if you’re afraid of being in a narrow or small space, talk with your doctor ahead of time. He or she may prescribe medication to help you be more comfortable.
  • If your doctor told you that you would receive anesthesia (medication to make you sleepy) while you have your MRI, you must follow these additional instructions:
    • Arrange for a responsible adult to take you home
    • Leave all valuables, such as credit cards and jewelry, at home.
    • If you wear contact lenses, wear your glasses instead.

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The Day of Your MRI

Between midnight and up until 2 hours before your scheduled arrival time, you may drink a total of 12 ounces of clear liquids (see Figure 1).

Figure 1. 12 ounces of clear liquid

Examples of clear liquids include:

  • Clear broth, bouillon, or consommé (no particles of dried food or seasonings) 
  • Gelatin, such as Jell-O® 
  • Clear fruit juices (no pulp), such as white cranberry, white grape, or apple 
  • Soda, such as 7-Up®, Sprite®, ginger ale, seltzer, or Gatorade® 
  • Coffee or tea, without milk or cream 

Things to remember

  • Take only the medications your doctor told you to take the morning of your procedure. Take them with a few sips of water.
  • If you are not receiving anesthesia you may eat and drink before your MRI, but please eat lightly.
  • Refer to the printed reminder you received from your doctor’s office for the time and location of your MRI.
  • If you wear a medication patch on your skin, bring an extra one with you. We may ask you to remove the patch before your MRI. This is because metal in the patch may heat up during your MRI and cause burns. If you wear a fentanyl patch, you can leave it on during your MRI.
  • If your doctor prescribed medication to help you relax during your MRI, bring it with you. Take it 30 to 60 minutes before your MRI.
  • Contrast dye might be used during your MRI to make it easier to see any disease. It will be given through an intravenous (IV) catheter placed in your hand or arm. If you have had a reaction to contrast dye in the past, call your doctor’s office. If you are going to get contrast dye, your doctor or nurse will discuss it with you first.
  • You will change into a hospital gown before going into the scanning area. For safety reasons, you will place your clothing, credit and ATM cards, and any objects (such as your phone, jewelry, coins, and glasses), in a locker. This is because objects with even a small amount of metal can fly into the magnet, and the magnet can damage items such as mobile phones and credit cards.
  • After you secure all of these items in your locker, you will be shown into the scanning room and helped onto the MRI table. The MRI scanner is a large, donut-shaped magnet. The scanner makes a constant tapping noise while the images are taken. Your technologist will offer you earplugs or earphones so that you can listen to music.
  • Just before your MRI starts, your nurse may give you an injection of a medication called glucagon. The glucagon will help your bowel relax, which will make the images better.
  • During the exam, you will lie in a small tunnel in the center of the MRI scanner. The tunnel is open at the end and there is a 2-way intercom system so that you can talk to your technologist. The intercom system also has a stereo. You can bring your favorite CDs to listen to while you are in the scanner. During your MRI, your technologist will take a number of different images of your prostate gland.
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After Your MRI

  • When your MRI is complete, the scanning table will be moved from the machine and you will be helped off the table. After you get your belongings, you may leave the MRI suite.
  • If you receive glucagon, a member of your radiology team will give you fruit juice, then a small snack (such as Fig Newton cookies). If you don’t feel well, tell a member of your radiology team.
  • There are no restrictions after your MRI. You may eat and drink as usual.
  • Your radiologist will send a report to your doctor. The results of your MRI will be used with other test results to plan your care.
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