Exploring uses of ultrasound in monitoring and treating IBD

Ultrasound imaging has long been used in healthcare to evaluate, diagnose, and monitor disease. According to the U.S. Food & Drug Administration, there are many types of ultrasounds, such as abdominal ultrasound (to view abdominal tissue and organs), bone sonometry (to assess bone density), doppler ultrasound (to visualize blood flow and look for blood clots in blood vessels, organs, or other structures), fetal ultrasound used in pregnancy, echocardiogram (to view the heart), and ophthalmic ultrasound (to view eye structures). Ultrasounds are also used to assist in medical procedures, like ultrasound-guided biopsies and ultrasound-guided needle placement.  


So why isn’t ultrasound utilized in inflammatory bowel disease (IBD)? Dr. Michael Dolinger, Assistant Professor of Pediatrics in the Division of Pediatric Gastroenterology at the Icahn School of Medicine at Mount Sinai, and a member of the International Bowel Ultrasound Group, is working with IBD clinicians around the world to train them in the use of intestinal ultrasound (IUS). Their goal? To expand the use of this minimally-invasive and cost-effective imaging tool to diagnose and monitor disease activity in Crohn’s disease and ulcerative colitis patients. 

What exactly is an intestinal ultrasound?

According to Dr. Dolinger, IUS is a routine abdominal ultrasound that can visualize the colon and the intestine. “It does not require any special bowel preparation [like colonoscopies], fasting, contrast, or have any side effects, such as radiation.”

When Dr. Dolinger was a gastroenterology trainee, he was unaware that ultrasound could be used for monitoring IBD. His mentor, Dr. Marla Dubinsky, also a Professor of Pediatrics in the Division of Pediatric Gastroenterology at the Icahn School of Medicine at Mount Sinai, shared with him that one of her publications as a trainee in the late 1990s was on ultrasound for the detection of Crohn’s disease activity. She wanted to bring this intestinal ultrasound to patients in the U.S. to continue advancements in the field, in this case for tight control disease activity monitoring, shared understanding, and decision-making to improve outcomes.


Still unsure what intestinal ultrasound was all about, Dr. Dolinger said he’d be willing to learn and attended an introductory International Bowel Ultrasound Course in Copenhagen, Denmark with other gastroenterologists from Europe, Canada, Israel, and Australia. “I was sold, especially seeing how ‘easy’ it was and the vivid resolution of the bowel that could be achieved in seconds just by placing an ultrasound probe on the patients in our hands-on portions of the conference,” he said.


So how does IUS work in IBD?

IUS monitors Crohn’s disease and ulcerative colitis by showing nearly the entire large intestine (colon) and the end of the small intestine (the terminal ileum). This visual allows healthcare professionals to measure several markers that correspond with IBD activity – specifically, the thickness of the bowel wall and increased blood flow by color Doppler signal. “The way that I explain this to patients is by making an analogy to inflammation that occurs for other reasons in the body, such as an injury to your knee for example. If you fall and hit your knee, it gets swollen and bruised. The same thing happens due to [IBD] activity in the colon and small intestine. The bowel wall becomes thickened (or swollen) and there is increased blood flow (or bruising),” Dr. Dolinger explains.

These markers of disease activity can normalize in response to medications used to treat IBD, such as biologics, and are followed closely by clinicians to assess treatment response and effectiveness. In a paper published in the Journal of Clinical Gastroenterology,  Dr. Dolinger and his colleagues explored the use of IUS to assess response to infliximab (Remicade) in pediatric Crohn’s disease patients with small bowel involvement. In this study, patients who were just starting on infliximab were enrolled. Disease activity, biomarkers (indicators of disease), and IUS findings were evaluated before they began taking the medication and assessed a second time after being on the medication for 14 weeks. The researchers hoped to describe the changes seen through the intestinal ultrasound both before and after the patients started infliximab, and how the changes were associated with other measures of treatment response. 

All the patients in the study achieved steroid-free remission and a decrease in C-reactive protein, a biomarker that indicates inflammation in the body, after starting infliximab. The patients also experienced a decrease in intestinal inflammation and small bowel involvement, which was seen on intestinal ultrasound. 

This study is also an example of the valuable information people living with IBD can help bring to light by participating in clinical trials. Through our Clinical Trials Community, you can learn more about  participating in clinical trials and find trials taking place in your area. Our helpful resources also include stories from research participants and highlights of findings from the most up-to-date IBD research. You can also start a conversation with your doctor on how clinical trials can play a role in your treatment.

How does IUS compare to other types of imaging

Some of the main differences between IUS and other types of imaging, like MRI or CT scans, include:
•    IUS does not involve exposure to radiation
•    IUS does not require oral or intravenous (IV) contrast
•    IUS can be performed at the bedside and in real-time
•    IUS doesn’t require any bowel preparation or fasting
•    IUS can be repeated often
•    Results from IUS are interpreted immediately during the examination 


Additionally, the visuals produced by intestinal ultrasound have excellent resolution that is comparable to MRI. “It’s a better tool for monitoring inflammation in the colon than MRI or CT scan,” Dr. Dolinger said.
However, IUS won’t replace MRI or CT scans as they can visualize certain things that IUS can’t. “MRI is a better tool to assess the length of small intestinal inflammation and inflammation higher up or more proximal in the small intestine,” Dr. Dolinger said.

Can IUS replace colonoscopies?

While IUS has many applications in disease management and treatment for IBD, it is meant to be used alongside colonoscopy, not as a replacement. There are certain things that can be done during a colonoscopy – like take biopsies and screen for colon cancer- that can’t be done during an intestinal ultrasound. However, there are a lot of advantages of intestinal ultrasound, including the precision and accuracy of the tool and the ability to get results in real time to help with shared decision-making between the patient and their healthcare team. Dr. Dolinger notes that IUS also has significant advantages for monitoring disease activity in specific IBD patient populations, such as those who are pregnant and those who have had surgery.

So how do we get IUS more widely used?

There is significant interest in the U.S. and around the world to use intestinal ultrasound in the care of IBD patients. However, Dr. Dolinger notes that training takes time to achieve expertise to use this tool for decision-making in care. “I believe in the next 5-10 years, intestinal ultrasound will become the standard rather than the exception for disease activity monitoring at IBD centers of excellence,” said Dr. Dolinger.


A recent training was held in New York for IBD clinicians to learn how to use intestinal ultrasound. Additional trainings will be held in 2023 in Chicago, Germany, and India to help further expand the use of this tool in the global IBD community.


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