Defecating Proctogram MRI

What is magnetic resonance imaging (MRI) scan?

Magnetic resonance imaging (MRI) uses a large magnet, radiofrequencies (sound), and a computer to make detailed pictures of organs and structures within the body.
The MRI machine is a large, doughnut-shaped machine that creates a strong magnetic field around the person being examined. Because MRI uses magnetic fields and sound waves to take pictures of the body there are no biological side-effects, as no radiation is used, unlike with X-ray or CT.

Why do I need an Defecating Proctogram MRI scan?

The test may help the clinician assess the floor of the pelvis for conditions such:
  • Difficulty opening or closing your bowels
  • Difficulty emptying your bladder
  • Abnormalities to the muscles of the floor of the pelvis

Because of the strong magnet in an MRI scanner, MRI cannot be used if you have:
  • Implanted pacemaker or cardiac defibrillator
  • Some intracranial aneurysm clips
  • Cochlear implants
  • Certain prosthetic devices
  • Implanted medicine infusion pumps or medicine ports
  • Neurostimulators
  • Bone-growth stimulators
  • Certain intrauterine contraceptive devices
  • Any other type of iron-based metal implants
  • Tattoos or body piercings
  • Internal metal objects or fragments, such as bullets or shrapnel, surgical clips, pins, plates, screws, metal sutures, or wire mesh

Tell your clinician if you are pregnant or think you may be. In general, there is no known risk of MRI in pregnancy. But in the first trimester, MRI should only be used to look at very important problems or suspected problems.
There may be other risks depending on your specific health condition. Be certain the radiographer knows about all of your health conditions.
Tell the radiographer doing the test if you:

  • Have ever had an imaging test (like MRI or CT) with contrast dye
  • Are allergic to contrast dye or any medicines
  • Have a serious health problem. This includes diabetes or kidney disease
  • Are pregnant or may be pregnant or are breastfeeding
  • Have any implanted device or metal clips or pins in your body

How do I get ready for an Defecating Proctogram MRI scan?

The radiographer will explain the procedure to you and give you a chance to ask any questions.
Generally, there is no special restriction on diet or activity before an MRI scan.
Before the MRI scan, it is very important that you tell the radiographer if any of these apply to you:
  • You are claustrophobic and think that you will be unable to lie still inside the scanning machine
  • You have a pacemaker or have had heart valves replaced
  • You have any type of implanted pump, such as an insulin pump
  • You have metal plates, pins, metal implants, surgical staples, or aneurysm clips
  • You have any metallic fragments anywhere in the body
  • You have permanent eyeliner or tattoos
  • You are pregnant or think you may be pregnant
  • You ever had a bullet wound
  • You have ever worked with metal (for example, a metal grinder or welder)
  • You have any body piercings
  • You have an intrauterine device (IUD)
  • You are wearing a medicine patch

If you are taking a sedative before the procedure, you should plan to have someone accompany you home afterward.

What happens during a Defecating Proctogram MRI scan?

A Defecography MRI lasts about 30 minutes. Some patients feel a small amount of discomfort from bloating or cramping during the exam.
Please arrive at the MRI Department 60 minutes before your scheduled exam. You will change into a hospital gown and your belongings will be safely locked away.
A member of the MRI team may need to perform an enema prior to the scan, depending on then you last opened your bowels. Once this is complete and you have emptied your rectum, an MRI staff person will bring you into the scanner room and you will lie on your side on the MRI table. The radiographer will then gently insert gel into your rectum through a small enema tip. You will then be asked to turn onto your back and you will stay in that position for the rest of the exam.
A special camera, called a coil, will be placed on top of your belly like a blanket. After positioning you in the MRI scanner, the MRI staff will move to the scanner control room that is right next to the room you will be in.
MRI staff will be able to see you and hear you at all times. You will also be given a call button in case you need to speak with the staff at anytime during the exam.
When the exam begins, the MRI scanner will make repeated knocking sounds as it is taking the pictures of your pelvis. You will be given earplugs or headphones to lessen the sound.
At times during the exam, the MRI staff person will ask you to 'bear down', 'relax', or 'hold in'.  You will also be asked to open your bowels onto the table so that a doctor can observe how your rectum empties.

What happens after a Defecating Proctogram MRI scan?

After the exam is complete, the staff will bring some towels to help clean up the gel. You will then be directed to the toilet to further clean up. Feel free to ask the MRI staff people for help if you need it.
Move slowly when getting up from the scanner table so you don't have any dizziness or light-headedness from lying flat for the length of the procedure.
If any sedatives were used for the scan, you may need to rest until the sedatives have worn off. You will also need someone to drive you home.
Otherwise, there is no special type of care required after a MRI scan of the Rectum. You may go back to your usual diet and activities, unless the radiographer tells you differently.
The radiographer may give you other instructions after the procedure, depending on your particular situation.
Last updated17 Feb 2021
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