An MR Enterography (Magnetic Resonance Enterography) uses strong magnetic fields and radio waves to capture highly detailed pictures of the small bowel, a long, coiled section of your digestive tract that is otherwise very difficult to examine.
Doctors request this scan to locate areas of severe inflammation, find hidden bleeding, or check for bowel blockages.
Unlike CT scans, MR Enterography uses zero radiation. Because conditions like Crohn's disease frequently affect young people who require repeated imaging over their lifetimes, avoiding X-ray radiation is a massive benefit.
Why would my doctor ask for an MR Enterography?
Your doctor may recommend an MR Enterography to look closely at your small intestine, especially if you have:
- Crohn's disease or ulcerative colitis (to check the severity of the inflammation and track if medications are working).
- Unexplained internal bleeding or severe abdominal pain.
- Persistent diarrhea or unexplained weight loss.
- Suspected blockages or tears in the intestinal wall.
What can an MR Enterography detect?
An MR Enterography helps doctors visualize:
- The entire length of the small intestine and its walls.
It is particularly useful for identifying:
- Active inflammation or swelling within the bowel walls.
- Strictures (areas where the bowel has narrowed and is causing a blockage).
- Fistulas (abnormal tunnel connections between the bowel and other organs).
- Abscesses (pus-filled pockets of infection).
- Tumors or polyps.
Do I need any special preparation for an MR Enterography?
Yes, this scan requires significant preparation compared to a standard MRI:
- Fasting: You must fast (no food or drink) for 4 to 6 hours prior to the exam.
- Early Arrival: You will be asked to arrive 1 to 2.5 hours before your actual scan time.
- Drinking the Contrast: During this waiting period, you will slowly drink multiple bottles of a special oral contrast liquid (such as VoLumen) in timed intervals.
- Remove all metal objects, jewelry, and body piercings, and change into a hospital gown.
Will I be injected with dye for this scan?
MR enterography protocols vary. Many centres use an antiperistaltic medicine, intravenous gadolinium, or both, but either may be omitted when contraindicated or unnecessary:
- Antiperistaltic medicine (such as glucagon or hyoscine, depending on local practice): This temporarily reduces bowel movement so the images are less blurred.
- Contrast Dye (Gadolinium): This dye highlights inflamed or diseased areas of the bowel wall, making them shine brightly on the screen.
What does an MR Enterography feel like?
Drinking the large volume of oral contrast is the most challenging part for many patients. You will likely feel very full, bloated, and may have a strong urge to use the bathroom (which is completely normal).
Once in the scanner, the test is painless. You will lie flat on your back or stomach. A special device will be placed over your abdomen to capture the signals. The machine makes loud knocking sounds, so you will wear earplugs. You will be asked to hold your breath for short periods to keep your stomach still while pictures are taken.
Is it safe for pregnant women or children?
Yes. MR Enterography avoids radiation, making it highly preferred for children and young adults with Crohn's disease. Pregnant women should consult their doctor; while the MRI itself is safe, the IV contrast dye is usually avoided during pregnancy unless absolutely necessary.
How long does the MR Enterography take?
While the time inside the MRI scanner is typically about 45 minutes, the entire appointment usually takes 2 to 3 hours because of the time required to drink the oral contrast beforehand.
When will I get my results?
After the scan, an abdominal Radiologist will review the images and prepare a detailed report. Your gastroenterologist or primary doctor will discuss the findings with you to adjust your medications or plan for any necessary surgical interventions.
Why do I have to drink so much liquid before the scan?
The small intestine is essentially a long, collapsed, muscular tube. If the tube is flat and empty, the radiologist cannot see the walls clearly. Drinking a large volume of the special oral contrast physically stretches and inflates (distends) the small bowel from the inside. This allows the radiologist to clearly see the thickness of the walls and accurately spot any inflammation or strictures.
What if I’m nervous about being inside the scanner?
It’s common to feel claustrophobic. You will be in constant contact with the Radiographer through an intercom. You will also have a call button you can squeeze if you need to stop or if you urgently need to use the restroom. You may ask your doctor for a mild sedative prior to your appointment if you are very anxious.
Sources and further reading
- RadiologyInfo: MRI of the body
- ACR Manual on Contrast Media
- FDA: Gadolinium retention safety communication
Conclusion
An MR Enterography is an incredibly powerful, safe, and radiation-free tool for evaluating the health of your small intestine. By providing crystal-clear images of inflammation and blockages, it is an essential procedure for effectively managing inflammatory bowel diseases and guiding long-term treatment.