Magnetic Resonance Enterography (MRE): A Safe, Accurate Imaging Solution for Small Bowel and Crohn’s Disease

What is an MRE?

Magnetic resonance enterography (MRE) is a special type of magnetic resonance imaging technique that produces highly detailed images of the small intestine to pinpoint different medical conditions, such as inflammation, bleeding, obstructions, and other problems. 

Unlike traditional imaging methods, MRE does not use ionising radiation but rather a magnetic field, radiofrequency pulses, and a computer to create cross-sectional images of the gastrointestinal (GI) tract, particularly the small bowel.

A healthcare professional will also administer medicine and oral or intravenous (IV) contrast dyes before the MRE to decrease the movement of the bowel and highlight the small intestine. This non-invasive technique is especially valuable for visualising soft tissue structures and detecting abnormalities in the intestines.

Why do I need an MRE?

Doctors often recommend MRE tests for those with Crohn’s disease. An MRE is especially helpful for checking and tracking inflammatory bowel diseases (IBD) because it can measure how much inflammation there is, find narrowed areas, and spot problems like tumours, abscesses, or fistulas.

Crohn's disease tends to strike young people, who are at greater risk of problems from repeated radiation exposure. MR enterography can help prevent unnecessary X-rays. Additionally, the procedure is more effective for viewing soft-tissue problems.

Your doctor may also recommend an MRE if you have symptoms suggestive of a small bowel disease, such as unexplained abdominal pain, chronic diarrhoea, or weight loss. An MRE is also used when other diagnostic tests, like endoscopy, are inconclusive or not feasible.

What does an MRE diagnose?

An MRE is primarily used to diagnose and monitor conditions affecting the small intestine, including:

• Internal bleeding

• Areas of irritation and swelling

• Crohn’s disease and other types of bowel inflammation

• Small tears in the intestinal wall

• Coeliac disease

• Small bowel tumours and blockages

• Abscesses

• Sources of unexplained GI bleeding

This test may also help track how well certain treatments are working.

If you have any concerns about the above conditions or a history of intestinal issues, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.

How do I prepare for an MRE?

Before an MRE, preparation typically involves:

• Blood tests:

  • If you have any preexisting kidney problems, blood tests may be required to ensure it is safe to receive the intravenous contrast agent.

• Fasting:

  • You may be asked not to eat or drink or stay away from certain foods for about 6 hours before the scan.

• Medical review with your doctor:

  • Inform your healthcare provider if you are pregnant, claustrophobic, or have any medications, allergies, or implanted medical devices (such as pacemakers, metal coils in your blood vessels, or cochlear implants), as these may affect your ability to undergo the scan.

  • If you suffer from claustrophobia, your healthcare provider may administer a sedative before the test.

• Wear loose and comfortable clothing:

  • Remove any jewellery, body piercings, or metal objects, including zips and hairpins. You may also need to change into a hospital gown before the test.

What happens during an MRE?

1. Upon arrival, you will need to change into a gown and be given oral contrast to drink over a period of time to help highlight your intestines. If necessary, a sedative will also be administered to help you relax.

2. The test will begin around 45 minutes after you drink the contrast material.

3. An IV line will be placed for administering contrast dye and medication to slow bowel movement, which helps produce clearer images. After the contrast dye injection, you might experience a metallic taste in your mouth.

4. You will lie on a table that slides into the MRI scanner. A lightweight coil will be placed over your abdomen.

5. The MRI machine will scan your body before the contrast dye is injected and afterwards. You will be alone in the room, but you can talk to the people operating the machine.

6. The machine may make some humming, bumping, or pinging noises as it scans you. Earplugs or headphones are provided to reduce noise from the scanner.

7. The scan itself takes about 30 to 45 minutes. You will need to remain still, and occasionally you may be asked to hold your breath for short periods.

8. When the exam is complete, the technologist may ask you to wait while the radiologist checks the images in case additional images are needed.

9. Afterwards, your healthcare provider will remove your IV line after the exam is over and place a small dressing over the insertion site.

After the scan, you can usually resume your usual activities immediately. You may experience mild nausea, cramping, or diarrhoea from the contrast material or other items injected or ingested. Let your healthcare provider know if you have any serious or ongoing discomfort.

How do I interpret the results of my MRE?

The images from your MRE will be reviewed by a radiologist, who will prepare a detailed report for your referring doctor. The report will describe any abnormalities, such as inflammation, strictures, or masses, and may include recommendations for further tests or treatment. Your doctor will discuss the results with you and explain what they mean for your diagnosis and management plan.

Are there any risks to an MRE?

MRE is generally considered very safe, but there are a few potential risks:

• The strong magnetic field can interfere with certain implanted medical devices.

• MR scanners may be very loud, with some machines reaching up to 120 decibels. To avoid hearing damage, you may need to wear protective headphones or earplugs.

• The intravenous contrast agent (gadolinium) is usually safe, but in rare cases, it can cause allergic reactions or kidney problems, especially in those with pre-existing kidney disease. Mild symptoms may resolve on their own. If you develop shortness of breath or difficulty breathing, seek emergency medical attention.

• Some people may experience mild side effects from the medications used to slow bowel movement, such as temporary blurred vision or a faster heartbeat.

• Claustrophobia or discomfort from lying still in the scanner may occur in some patients.

FAQ

What does an MRI enterography show?

MRI enterography provides detailed images of the small intestine, allowing doctors to identify inflammation, strictures, fistulas, abscesses, and other abnormalities in the bowel wall and surrounding tissues.

What's the difference between an MRI and an MRE?

Despite using the same MRI technology, MRE specifically targets the small intestine for imaging. An MRE requires special preparation, including drinking oral contrast, and is optimised to detect bowel diseases, whereas a standard MRI may focus on other organs or body parts.

What is an MRE scan used for?

An MRE scan is used to diagnose and monitor small bowel diseases, particularly Crohn’s disease, but also other conditions, such as coeliac disease, small bowel tumours, and unexplained GI bleeding.

How do you prepare for magnetic resonance enterography?

Preparation involves fasting, drinking oral contrast, reviewing medications and medical history with your doctor, and sometimes having blood tests to check kidney function.

Is MRE the same as MRI?

MRE is a specific application of MRI technology focused on the small intestine. All MREs are MRIs, but not all MRIs are MREs.

What is the MRE for Crohn's disease?

For Crohn’s disease, MRE is used to assess the location, extent, and severity of inflammation, detect complications, and monitor response to treatment. It is a preferred imaging method because it avoids radiation and provides excellent soft tissue detail.

What are the side effects of the MRE?

Most people tolerate MRE well. Possible side effects include mild discomfort from the oral contrast, temporary blurred vision or increased heart rate from medications, and rare allergic reactions to the contrast dye.

Can MREs cause stomach problems?

Some patients may experience mild bloating, nausea, or diarrhoea from the oral contrast, but these symptoms are usually temporary and resolve soon after the test.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.