Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New techniques improve imaging quality, not diagnosis of Barrett's esophagus

13.03.2008
Novel techniques to improve the quality of imaging are helping doctors get a better look at esophageal conditions such as Barrett’s esophagus (BE), but they do not necessarily improve the diagnosis or physician agreement on images, according to a study published this month in Gastroenterology, the official journal of the American Gastroenterological Association (AGA) Institute.

Researchers from the study found that the image quality of magnified images of BE that are obtained with new imaging techniques was preferred both by expert and by non-expert endoscopists. However, this higher preference did not lead to more agreement on features of interest and did not improve their ability to diagnose esophageal abnormalities.

“We know that novel technologies are dramatically improving image quality, which in turn has improved the diagnostic potential of minimally invasive techniques. But we need to review these techniques to fully understand if they deliver a clinical benefit rather than just a clearer image,” said Jacques Bergman, MD, PhD, from the Academic Medical Center in the Netherlands and lead author of the study. “In our opinion, the subjective improvement of image quality with enhancement techniques may have limited clinical relevance in this particular setting.”

In this study, the research team compared images obtained with magnifying high-resolution white light endoscopy (WLE, a standard endoscopic process), narrow band imaging (NBI), indigo carmine chromoendoscopy (ICC) and acetic acid chromoendoscopy (AAC) to determine the best techniques for detailed evaluation of BE characteristics. The team evaluated the improved quality of the images and sought to determine if the addition of these enhancement techniques would improve the agreement between observers for distinct features of disease as well as their ability to correctly identify abnormal areas. Because dysplastic and non-dysplastic BE features are associated with different visual characteristics (mucosal and vascular patterns and/or the presence of abnormal blood vessels), the type of imaging may offer improved visual diagnosis of abnormalities in the esophageal mucosal tissue.

When the enhancement techniques were compared with regular WLE images, the observers clearly preferred the enhancement techniques, which scored higher in terms of overall image quality, the quality of mucosal imaging, and the quality of vascular imaging. NBI and AAC were the most often preferred techniques and were rated best for overall image quality (43 and 40 percent of comparisons, respectively). WLE and ICC were ranked most often as the worst techniques (38 and 39 percent of comparisons, respectively). All three enhancement techniques (NBI, ICC or AAC) scored better than WLE for most image quality characteristics, but AAC rated the highest for mucosal image quality (80 percent of evaluations scored better than WLE), while NBI rated the highest for vascular image quality (60 percent of evaluations scored better than WLE).

However, the study found that the higher image quality did not translate into a clinically relevant benefit. The observer agreement was moderate on the three factors assessed on the WLE images (mucosal irregularity, vascular irregularity or the presence of abnormal blood vessels), and when WLE was combined with NBI, ICC or AAC, observer agreement did not improve. More so, expert and non-expert endoscopists did not agree more on their interpretation even when they compared all images obtained with additive techniques to WLE images of the same area.

Adding enhancement techniques also did not improve the diagnosis of neoplasia in the study. The yield for identifying early neoplasia with white light images was 86 percent for all observers, 90 percent for experts and 84 percent for non-experts, and when comparing all images, yield ranged from 70 to 86 percent for all observers. The researchers speculated on the possibility that most of the essential information may already have been present in the high-quality WLE images, or that the interpretation of the images may vary widely amongst endoscopists, which may explain the finding that expert endoscopists had a lower agreement for mucosal patterns compared to non-experts (ê = 0.43 vs. ê = 0.64).

Participants in the study were undergoing either surveillance endoscopies of known BE or work-ups of high-grade intraepithelial neoplasia (HGIN, a precancerous condition) or early cancer (EC). Conditions diagnosed in study patients included eight areas with HGIN/EC, one with low grade dysplasia, one with indefinite for dysplasia and 12 areas with non-dysplastic BE. After each patient received endoscopic imaging using WLE and each additive technique, the highest quality image from each technique was selected for analysis. The images were evaluated by seven endoscopists with no specific expertise in BE or advanced endoscopic imaging techniques and five endoscopists with experience in advanced imaging techniques and in BE to compare expert versus non-expert opinions.

Chromoendoscopy is a technique in which staining agents are applied to the gastrointestinal tract to improve the images of the esophageal mucosa captured during endoscopies. The stains enable technicians to see surface patterns or functional characteristics that may suggest early neoplasia, lesions that are difficult to detect with standard endoscopy. Recently, a new optical technique, NBI, was developed that uses light that penetrates the tissue at varying levels depending on the chosen wavelength. Light of a short wavelength (e.g. blue light in the visible spectrum) penetrates very little, allowing for improved surface detail imaging. Two other additives were applied to chromoendoscopy for this study – ICC and AAC.

Aimee Frank | EurekAlert!
Further information:
http://www.gastro.org

More articles from Medical Engineering:

nachricht Novel PET tracer identifies most bacterial infections
06.10.2017 | Society of Nuclear Medicine and Molecular Imaging

nachricht Teleoperating robots with virtual reality
05.10.2017 | Massachusetts Institute of Technology, CSAIL

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>