New 3-D colonoscopy eases detection of precancerous lesions

July 31, 2013 by Anne Trafton

MIT researchers have developed a new endoscopy technology that could make it easier for doctors to detect precancerous lesions in the colon. Early detection of such lesions has been shown to reduce death rates from colorectal cancer, which kills about 50,000 people per year in the United States.

The new technique, known as photometric stereo , can capture topographical images of the colon surface along with traditional two-dimensional images. Such images make it easier to see , including flatter lesions that traditional endoscopy usually misses, says Nicholas Durr, a research fellow in the Madrid-MIT M+Vision Consortium, a recently formed community of in Boston and Madrid.

"In conventional screening, you look for these characteristic large polyps that grow into the of the colon, which are relatively easy to see," Durr says. "However, a lot of studies in the last few years have shown that more subtle, nonpolypoid lesions can also cause cancer."

Durr is the senior author of a paper describing the new technology in the Journal of Biomedical Optics. Lead author of the paper is Vicente Parot, a research fellow in the M+Vision Consortium. Researchers from Massachusetts General Hospital (MGH) also participated in the project.

In the United States, colonoscopies are recommended beginning at age 50, and are credited with reducing the risk of death from colorectal cancer by about half. Traditional colonoscopy uses endoscopes with fiber-optic cameras to capture images.

Durr and his colleagues, seeking that could be solved with new , realized that there was a need to detect lesions that colonoscopy can miss. A technique called chromoendoscopy, in which a dye is sprayed in the colon to highlight topographical changes, offers better sensitivity but is not routinely used because it takes too long.

"Photometric stereo endoscopy can potentially provide similar contrast to chromoendoscopy," Durr says. "And because it's an all-optical technique, it can give the contrast at the push of a button."

Originally developed as a computer vision technique, photometric stereo imaging can reproduce the topography of a surface by measuring the distances between multiple light sources and the surface. Those distances are used to calculate the slope of the surface relative to the light source, generating a representation of any bumps or other surface features.

However, the researchers had to modify the original technology for endoscopy because there is no way to know the precise distance between the tip of the endoscope and the surface of the colon. Because of this, the images generated during their first attempts contained distortions, particularly in locations where the surface height changes gradually.

To eliminate those distortions, the researchers developed a way to filter out spatial information from the smoothest surfaces. The resulting technology, which requires at least three light sources, does not calculate the exact height or depth of surface features but creates a visual representation that allows the colonoscopist to determine if there is a lesion or polyp.

"What is attractive about this technique for colonoscopy is that it provides an added dimension of diagnostic information, particularly about three-dimensional morphology on the surface of the colon," says Nimmi Ramanujam, a professor of biological engineering at Duke University who was not part of the research team.

The researchers built two prototypes—one 35 millimeters in diameter, which would be too large to use for colonoscopy, and one 14 millimeters in diameter, the size of a typical colonoscope. In tests with an artificial silicon colon, the researchers found that both prototypes could create 3-D representations of polyps and flatter lesions.

The new technology should be easily incorporated into newer endoscopes, Durr says. "A lot of existing colonoscopes already have multiple light sources," he says. "From a hardware perspective all they need to do is alternate the lights and then update their software to process this photometric data."

The researchers plan to test the technology in human patients in clinical trials at MGH and the Hospital Clinico San Carlos in Madrid. They are also working on additional computer algorithms that could help to automate the process of identifying and lesions from the topographical information generated by the new system.

Explore further: New colonoscope provides ground-breaking view of colon

Related Stories

New colonoscope provides ground-breaking view of colon

May 18, 2013
A ground-breaking advance in colonoscopy technology signals the future of colorectal care, according to research presented today at Digestive Disease Week(DDW). Additional research focuses on optimizing the minimal withdrawal ...

Too many americans skipping colon cancer screening

March 2, 2012
(HealthDay) -- Approximately one in three U.S. adults between the ages of 50 and 75 who should be screened for colorectal cancer have not been, according to the American Society for Gastrointestinal Endoscopy.

Use of a retroflexion technique during colonoscopy in the right side of the colon improves polyp detection

August 4, 2011
A new study from researchers in Indiana reports that use of a retroflexion technique in the right side of the colon during colonoscopy is safe and results in the detection of additional adenomatous (precancerous) polyps in ...

Increased use of colonoscopy screening could explain decrease in colorectal cancer rates

October 23, 2012
Use of colonoscopy for colorectal cancer screening could explain a significant decrease in the cancer's incidence over the past decade, according to a new study from researchers at the Stanford University School of Medicine. ...

Laxative-free CT colonography may be as accurate as colonoscopy in detecting high-risk polyps

May 14, 2012
A CT-scan-based form of virtual colonoscopy that does not require laxative preparation appears to be as effective as standard colonoscopy in identifying the intestinal polyps most likely to become cancerous. In the May 15 ...

Poor colonoscopy prep hides pre-cancerous polyps

March 27, 2012
(Medical Xpress) -- What happens on the day before a colonoscopy may be just as important as the colon-screening test itself.

Recommended for you

Vitamin C may encourage blood cancer stem cells to die

August 17, 2017
Vitamin C may "tell" faulty stem cells in the bone marrow to mature and die normally, instead of multiplying to cause blood cancers. This is the finding of a study led by researchers from Perlmutter Cancer Center at NYU Langone ...

Scientists develop novel immunotherapy technology for prostate cancer

August 17, 2017
A study led by scientists at The Wistar Institute describes a novel immunotherapeutic strategy for the treatment of cancer based on the use of synthetic DNA to directly encode protective antibodies against a cancer specific ...

Outdoor light at night linked with increased breast cancer risk in women

August 17, 2017
Women who live in areas with higher levels of outdoor light at night may be at higher risk for breast cancer than those living in areas with lower levels, according to a large long-term study from Harvard T.H. Chan School ...

Toxic formaldehyde is produced inside our own cells, scientists discover

August 16, 2017
New research has revealed that some of the toxin formaldehyde in our bodies does not come from our environment - it is a by-product of an essential reaction inside our own cells. This could provide new targets for developing ...

Cell cycle-blocking drugs can shrink tumors by enlisting immune system in attack on cancer

August 16, 2017
In the brief time that drugs known as CDK4/6 inhibitors have been approved for the treatment of metastatic breast cancer, doctors have made a startling observation: in certain patients, the drugs—designed to halt cancer ...

Researchers find 'switch' that turns on immune cells' tumor-killing ability

August 16, 2017
Molecular biologists led by Leonid Pobezinsky and his wife and research collaborator Elena Pobezinskaya at the University of Massachusetts Amherst have published results that for the first time show how a microRNA molecule ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.