Photoacoustic endoscopy could improve Crohn's disease treatment

April 24, 2019

WASHINGTON -- A newly developed endoscope could give doctors a better view of intestinal changes caused by Crohn's disease. This additional information would help improve treatment of the painful and debilitating form of inflammatory bowel disease, which currently affects hundreds of thousands of U.S. adults.

Researchers from the University of Michigan describe the new device in The Optical Society (OSA) journal Biomedical Optics Express. The endoscope is used for photoacoustic imaging, a relatively new biomedical imaging method that uses light to produce sound waves in tissue that can be captured with ultrasound imaging.

"This new imaging technology could help more accurately plan therapy for each Crohn's disease patient," said Guan Xu, leader of the research team. "This would allow more targeted treatment and help minimize any adverse effects that might result from treatment."

Making treatment decisions

In Crohn's disease, both inflammation and fibrosis cause the development of strictures -- areas of narrowing -- in the intestines. Although strictures caused by inflammation can be treated with drugs, the ones caused by fibrosis must be removed surgically.

"Currently, there is no imaging modality that can be used in the intestine to distinguish inflammation from fibrosis," said Xu. "The difficulty in accurately assessing the presence and development of ?brosis in the strictures adds a great deal of complexity to Crohn's disease management decisions."

In the new study, the researchers developed a capsule-shaped photoacoustic imaging endoscope to examine whether this imaging technique could be used to characterize inflammation and fibrosis in intestinal strictures. The capsule-shaped probe was 7 millimeters in diameter and 19 millimeters long.

They designed the endoscope to deliver near infrared light at 1310 nanometers because this wavelength is absorbed by collagen protein, which is characteristic of fibrosis. The light absorption causes the protein to expand slightly, leading to a mechanical vibration that can be captured using ultrasound imaging. To generate a strong signal, the researchers constructed the endoscope to maximize delivery of 1310-nanometer light.

Distinguishing inflammation and fibrosis

The researchers tested their new endoscope in rabbit models with intestinal narrowing caused by either inflammation only or a mix of fibrosis and inflammation. The experiments showed the endoscopic photoacoustic imaging approach could quantitatively differentiate inflammatory from fibrotic intestinal strictures. Another study in rabbits demonstrated that the endoscope could also quantify the development of fibrosis over time.

"The method we demonstrated is minimally invasive and can directly assess fibrosis in the intestinal stricture, which has not been demonstrated by conventional medical imaging modalities," said Xu.

The researchers are now working to make the endoscope small enough to pass through the instrument channel of a colonoscope, a flexible fiber-optic instrument used to examine the large intestine. This could provide a surgeon with diagnostic information immediately before treatment without the need for additional procedures.
-end-
Paper: H. Lei, L. A. Johnson, K. A. Eaton, S. Liu, J. Ni, X. Wang, P. D. R. Higgins, G. Xu, "Characterizing intestinal strictures of Crohn's disease in vivo by endoscopic photoacoustic imaging," Biomed. Opt. Express, volume 10, issue 5, pp. 2542-2555 (2019). DOI: https://doi.org/10.1364/BOE.10.002542

About Biomedical Optics Express

Biomedical Optics Express is OSA's principal outlet for serving the biomedical optics community with rapid, open-access, peer-reviewed papers related to optics, photonics and imaging in the life sciences. The journal scope encompasses theoretical modeling and simulations, technology development, and biomedical studies and clinical applications. It is published by The Optical Society and edited by Christoph Hitzenberger, Medical University of Vienna. Biomedical Optics Express is an open-access journal and is available at no cost to readers online at OSA Publishing.

About The Optical Society

Founded in 1916, The Optical Society (OSA) is the leading professional organization for scientists, engineers, students and business leaders who fuel discoveries, shape real-life applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership initiatives, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of optics and photonics experts. For more information, visit osa.org.

Media Contact: mediarelations@osa.org

The Optical Society

Related Inflammatory Bowel Disease Articles from Brightsurf:

People with inflammatory bowel disease still die earlier despite increase in life
A study comparing life expectancy of people with inflammatory bowel disease (IBD) and without found that, while life expectancy increased for both groups, people with IBD generally died sooner.

Cell therapy designed to treat inflammatory bowel disease
The UPV/EHU's NanoBioCel research group has for many years been developing systems enabling cells to be used as drugs.

Team develops wearable sensor to help people with inflammatory bowel disease
University of Texas at Dallas researchers have designed a wearable device that monitors sweat for biomarkers that could signal flare-ups of inflammatory bowel disease (IBD).

Antibiotics associated with increased risk of inflammatory bowel disease
Antibiotics use, particularly antibiotics with greater spectrum of microbial coverage, may be associated with an increased risk of new-onset inflammatory bowel disease (IBD) and its subtypes ulcerative colitis and Crohn's disease.

Yes, inflammatory bowel disease and celiac disease are linked
A systematic review and meta-analysis that has determined there is a nine-fold increased risk of having IBD for patients with a previous diagnosis of celiac disease.

The effects of inflammatory bowel disease on pregnancy
Inflammatory bowel disease (IBD) -- including Crohn's disease and ulcerative colitis -- often affects women of childbearing age.

5 major advances in inflammatory bowel disease (IBD) treatment
Summary of five impactful studies to be presented at the Crohn's & Colitis Congress, a partnership of the Crohn's & Colitis Foundation and the American Gastroenterological Association (AGA).

Researchers identify a possible cause and treatment for inflammatory bowel disease
In a study published online in PNAS on Jan. 20, 2020, Prof.

Does inflammatory bowel disease carry certain risks during pregnancy?
Pregnant women with inflammatory bowel disease (IBD) are more likely to undergo delivery by Caesarean section and face certain risks during pregnancy, according to an analysis published in Alimentary Pharmacology & Therapeutics.

Inhibiting a protease could improve the treatment of inflammatory bowel disease
Scientists at the CNIC and CSIC have identified a function of a protease that could be the future target of drugs to treat inflammatory bowel disease.

Read More: Inflammatory Bowel Disease News and Inflammatory Bowel Disease Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.