Magnetic Resonance Enterography

(Magnetic Resonance Enterography)

Procedure overview

Magnetic resonance enterography, or MR enterography, is a minimally invasive imaging test that allows your doctor to obtain detailed pictures of your small bowel. It can pinpoint areas of inflammation (swelling and irritation), bleeding, and other small bowel conditions.

The Digestive Tract. Click to Enlarge

The procedure uses a magnetic field to create detailed images of your organs. These can then be analyzed on a computer and copied to a printer or CD. In MR enterography, an oral contrast dye is used to highlight the small bowel, also known as the small intestine.

This is not an X-ray procedure, so it does not involve any kind of radiation. The oral contrast material does not contain any radioactive material. The images produced by this procedure are quite detailed. The procedure may take around 45 minutes to complete.

Reasons for the procedure

MR enterography may be recommended to:

• Find internal bleeding

• Find areas of irritation and swelling

• Find abscesses, which are pus filled pockets, in the intestinal walls

• Find small tears in the intestine wall

• Find any blockages or obstructions

• Help track how well certain treatments are working

MR enterography is often recommended when you have Crohn's disease and are likely to need many follow-up imaging tests. Crohn's disease tends to strike young people, who are at particular risk from X-ray radiation. MR enterography can help avoid getting unnecessary doses of X-rays, also called ionizing radiation. Also, the procedure is better than CT scans for subtle soft-tissue problems. It captures excellent images of fluid and swelling, as well as active inflammation, bowel obstructions, abscesses, and fistulas, or abnormal passageways between organs.

Risks of the procedure

MR enterography carries some risks:

• The magnetic field may change the way any implanted medical devices work.

• It may damage the kidneys, especially in people whose kidneys are not working well.

• Some patients have an allergic reaction to the contrast dye.

There may be other risks, depending upon your specific medical condition. Be sure to discuss any concerns with your doctor before the procedure.

Before the procedure

Before having MR enterography, you will likely need to:

• Complete any blood tests or other tests ordered by your doctor.

• Let your doctor know if you are or could be pregnant.

• Let your doctor know if you have any implanted medical devices or use any devices regularly, such as hearing aids. Some types of devices may disqualify you from this procedure. For example, if you have an implanted defibrillator or pacemaker, a cochlear ear implant, a clip for a brain aneurysm, or a metal coil in your blood vessels, you should not have this procedure or enter the MRI area unless instructed to do so by your radiologist.

• Make sure you understand why the procedure was recommended.

• Ask your doctor if you should stop taking any of your regular medications or supplements. You may need to stop taking medications or other agents that could thin your blood before the procedure.

• Ask your doctor when to stop eating and drinking or whether you should avoid certain foods for this test. You may be asked not to eat or drink for six hours before the test.

• Let your doctor know about any allergies or other health conditions, such as diabetes or kidney disease.

• Talk with your radiologist or doctor about whether you might need a sedative to relax during the test. 

• Do not wear any jewelry or body piercings, or bring any valuable personal items to the procedure.

• Do not carry any metal objects into the exam room. This includes hairpins and metal zippers.

• If you have sensitive hearing, ask for earplugs to wear during the procedure. The MRI machine can make loud noises that some people may find disturbing.

• If you will be discharged the same day, make sure you have an adult who can drive you home, in case you are given a sedative before the procedure.

During the procedure:

• You will be given a gown to change into and wear during the procedure, and you may be given a sedative to help you relax.

• You'll be given water and a contrast material to drink in advance of the procedure. Your procedure will begin about 45 minutes after you start drinking.

• Medical staff will help position and secure you on a table in the exam room. The more still you are, the better the images will be.

• A nurse may start an IV so that you can be given fluids and injected contrast material in addition to the swallowed contrast.

• The MRI machine will scan your body before the contrast dye is injected and afterward. You will be alone in the room, but you can talk to the people operating the machine. The machine may make some humming, bumping, or pinging noises as it scans you. This is normal.

• You may be asked to briefly hold your breath.

• You may need to stay in place while the images are reviewed. If necessary, additional images will be created.

After the procedure

Some people experience mild nausea, cramping, or diarrhea from the contrast material ingested. Let your doctor know if you have any serious or ongoing discomfort.