High-definition Endoscopy Research Articles

COLOR CORRECTION FOR HIGH-DEFINITION ELECTRONIC ENDOSCOPE

The subtle color distinction is the important function of electronic endoscope imaging diagnosis. However, after image acquisition, transmission and display, color distortions of intracorporeal organs or tissues occur inevitably, which are adverse to analyze image features accurately or to diagnose early pathological changes. A real-time color correction algorithm based on four-neighborhood and polynomial regression in YUV color space is proposed. Based on polynomial regression the color correction matrix is calculated in YUV color space according to the differences between standard values of color checker and measured values of that imaged by the endoscope. As the correction is only executed on U and V components in YUV color space, the defect that the color of corrected images in RGB color space will change along with luminance can be avoided, and then the stability of image color is improved. Owing to four-neighborhood processing, the signal-to-noise ratio of corrected images is enhanced and the processing speed of correction algorithm is accelerated. The average color difference is reduced from 0.3944 to 0.2850 by application of the proposed algorithm in high-definition electronic endoscope. A total of 17 frames per second can be achieved at the resolution of 1280 × 800, and the color characteristics of the image after processing match that of human visual system.

Actualizaciones en las lesiones precursoras de cáncer colorrectal

The adenoma-carcinoma sequence is currently well established, and therefore, the potential for adenomas to progress to colorectal cancer (CRC). In the last decade, there has been a change in the paradigm that considered these lesions as the only precursors of CRC and nowadays serrated polyps are also considered to have the potential for malignant transformation.The studies presented this year at the congress of the American Gastroenterological Association provide important information to improve the characterization of CRC precursor lesions, especially as regards their detection, prevalence and treatment and surveillance strategies. Notable among these studies were those focussing on evaluating the epidemiological characteristics of serrated polyps and those attempting to improve the quality of colonoscopy -with the ultimate aim of achieving greater detection of these precursor lesions- by evaluating colon cleansing, the polyp detection rate, withdrawal times, the use of endoscopic caps, narrow band imaging, high-definition endoscopy and, lastly, adequate endoscopic surveillance.

Techniques for the laryngology assistant: providing optimal visualization

Many laryngologic procedures require assistant-driven visualization to optimize the surgeon's movements. Expanding technology, such as distal chip and high definition endoscopy improves visualization of the larynx, whereas improved instrumentation, such as malleable needles and fiber-based laser systems allow for novel therapeutic access to laryngeal pathology. Combining these technologies through various approaches may uncouple or couple surgical instrumentation from the laryngoscope, varying the role and expectations of the assistant. This article describes the authors' methods for operationalizing assistant-driven visualization for laryngologic procedures.

High-definition vs. standard-definition colonoscopy in the characterization of small colonic polyps: results from a randomized trial

The resolution of endoscopes has increased in recent years. Modern Fujinon colonoscopes have a charge-coupled device (CCD) pixel density of 650,000 pixels compared with the 410,000 pixel CCD in standard-definition scopes. Acquiring high-definition scopes represents a significant capital investment and their clinical value remains uncertain. The aim of the current study was to investigate the impact of high-definition endoscopes on the in vivo histology prediction of colonic polyps. Colonoscopy procedures were performed using Fujinon colonoscopes and EPX-4400 processor. Procedures were randomized to be performed using either a standard-definition EC-530 colonoscope or high-definition EC-530 and EC-590 colonoscopes. Polyps of <10 mm were assessed using both white light imaging (WLI) and flexible spectral imaging color enhancement (FICE), and the predicted diagnosis was recorded. Polyps were removed and sent for histological analysis by a pathologist who was blinded to the endoscopic diagnosis. The predicted diagnosis was compared with the histology to calculate the accuracy, sensitivity, and specificity of in vivo assessment using either standard or high-definition scopes. A total of 293 polyps of <10 mm were examined–150 polyps using the standard-definition colonoscope and 143 polyps using high-definition colonoscopes. There was no difference in sensitivity, specificity or accuracy between the two scopes when WLI was used (standard vs. high: accuracy 70% [95% CI 62–77] vs. 73% [95% CI 65–80]; P=0.61). When FICE was used, high-definition colonoscopes showed a sensitivity of 93% compared with 83% for standard-definition colonoscopes (P=0.048); specificity was 81% and 82%, respectively. There was no difference between high- and standard-definition colonoscopes when white light was used, but FICE significantly improved the in vivo diagnosis of small polyps when high-definition scopes were used compared with standard definition.

PWE-101 High definition endoscopy increases the number of adenomas detected in the UK bowel cancer screening population

IntroductionAdenoma detection and removal is one of the main goals of colonoscopy. Improved adenoma detection has been shown to reduce future risk of colorectal cancer. High definition colonoscopy allows better...

High-definition endoscopy with i-scan enables diagnosis of characteristic mucosal lesions in Whipple's disease

High-definition endoscopy with i-scan enables diagnosis of characteristic mucosal lesions in Whipple's disease

New three‐dimensional head‐mounted display system, TMDU‐S‐3D system, for minimally invasive surgery application: Procedures for gasless single‐port radical nephrectomy

We present an application of a new three-dimensional head-mounted display system that combines a high-definition three-dimensional organic electroluminescent head-mounted display with a high-definition three-dimensional endoscope to minimally invasive surgery, using gasless single-port radical nephrectomy procedures as a model. This system presents the surgeon with a higher quality of magnified three-dimensional imagery in front of the eyes regardless of head position, and simultaneously allows direct vision by moving the angle of sight downward. It is also significantly less expensive than the current robotic surgery system. While carrying out gasless single-port radical nephrectomy, the system provided the surgeon with excellent three-dimensional imagery of the operative field, direct vision of the outside and inside of the patient, and depth perception and tactile feedback through the devices. All four nephrectomies were safely completed within the operative time, blood loss was within usual limits and there were no complications. The display was light enough to comfortably be worn for a long operative time. Our experiences show that the three-dimensional head-mounted display system might facilitate maneuverability and safety in minimally invasive procedures, without prohibitive cost, and thus might mitigate the drawbacks of other three-dimensional vision systems. Because of the potential benefits that this system offers, it deserves further refinements of its role in various minimally invasive surgeries.

Comparison of High Definition with Standard White Light Endoscopy for Detection of Dysplastic Lesions During Surveillance Colonoscopy in Patients with Colonic Inflammatory Bowel Disease

Dysplasia in colonic inflammatory bowel disease (IBD) is often multifocal and flat. High-definition (HD) colonoscopy improves adenoma detection rates by improving the ability to detect subtle mucosal changes. The utility of HD colonoscopy in dysplasia detection in patients with IBD has not been reported so far. We aimed to compare the yield of dysplastic lesions detected by standard definition (SD) white light endoscopy with HD endoscopy. A retrospective cohort study of patients with long-standing (>7 years) colonic IBD undergoing surveillance colonoscopy at Nottingham University Hospital was studied between September 2008 and February 2010. Details of diagnosis, duration of disease, and outcomes of the colonoscopy were collected from the endoscopy database, electronic patient records, and patient notes. There were 160 colonoscopies (101 ulcerative colitis [UC] and 59 Crohn's disease [CD]) in the SD group and 209 colonoscopies (147 UC and 62 CD) in the HD group. The groups were well matched for all demographic variables. Thirty-two dysplastic lesions (27 on targeted biopsy) were detected in 24 patients in the HD group and 11 dysplastic lesions (six on targeted biopsy) were detected in eight patients the SD group. The adjusted prevalence ratio of detecting any dysplastic lesion and dysplastic lesion on targeted biopsy was 2.21 (95% confidence interval [CI] 1.09-4.45) and 2.99 (95% CI 1.16-7.79), respectively, for HD colonoscopy. HD colonoscopy improves targeted detection of dysplastic lesions during surveillance colonoscopy of patients with colonic IBD in routine clinical practice. Randomized controlled studies are required to confirm these findings.

Tu1675 Interobserver and Intraobserver Variation in the Diagnosis of Minimal Change Esophagitis by High Definition and I-SCAN Upper Endoscopy

Interobserver and Intraobserver Variation in the Diagnosis of Minimal Change Esophagitis by High Definition and I-SCAN Upper Endoscopy Jaksin Sottisuporn*, Nisa Netinatsunton, Naichaya Chamroonkul, Teepawit Witeerungrot, Theeratus Jongboonyanuparp, Siriboon Attasaranya, Bancha Ovartlarnporn NKC institute of Gastroenterology and Hepatology, Hatyai, Thailand Background: Minimal changes esophagitis lesions (MCL) has been regarded as one of the spectrum of erosive esophagitis in some studies. The MCLs are subtle changes and are difficult to identify by conventional endoscopy. I-Scan endoscopy (SE) is a new imaging technology that enhances the mucosal details. Limited studies showed the SE to be better than white light endoscopy in detecting MCL. The intraobserver and interobserver variations of SE in detecting MCL have never been reported before. Aim: To assess the intraand interobserver variations in detecting MCL by high-definition endoscopy (HD) and SE in tone enhancement mode for esophagus (TE-e) in dyspeptic patients. Method: The endoscopic images in HD and TE-e modes of distal esophagus of all patients with upper abdominal symptoms scheduled for upper gastrointestinal endoscopy at the NKC institute from February 2010 till August 2011 were used to assess the consistency of images interpretation by 6 endoscopists. A set of images representing MCL that included punctate erythema (PE), blurred vessels (BV), minute erosion (ME) and triangular lesion with elongated pit (TLE) were used to educate all the endoscopists. 6 endoscopists randomly evaluated the endoscopic images of 89 patients in HD and TE-e mode twice with at least 24 hours interval in between. The intra and inter-observer consistency of images interpretation was analyzed. Result: Intraobserver kappa values (95% CI) for HD group were 0.44(0.24-0.65), 0.44(0.24-0.65), 0.410.2-0.62), 0.59(0.39-0.8), 0.45(0.24-0.65), 0.13(0.00-0.34) and for TE-e SE were 0.35(0.15-0.56), 0.56(0.360.77), 0.97(076-1.00), 0.51(0.31-0.71), 0.44 (0.61-0.27), 0.32(0.11-0.53) respectively. These represent fair to excellent agreement for intraobserver image interpretation in both HD and TE-e. One of the endoscopist had significant improvement in detecting MCL on the second image interpretation (kappa 0.13 versus 0.32 p 0.05). In the interobserver consistency of image interpretation, the pairwise kappa values for HD and TE-e of all 6 endoscopists were rather low (range 0.16-0.3 and 0.05-0.37 respectively). When the evaluations in both groups were analyzed by pairing individual endoscopist into 15 pairs, the kappa values improved with agreement in 7 of 15 pairs without statistical significance. (p 1) Conclusions: The intraobsever agreement for MCL by HD and i-Scan is fair to excellent. The poor interobserver agreement by HD and TE-e for MCL limits the value of the MCL in clinical practice. The SE imaging technology did not improve the interobserver image interpretation consistency.

Sa1584 Minimal Change Esophagitis by High Definition Endoscopy and I-SCAN Endoscopy in Dyspeptic Patients With or Without Gastroesophareal Reflux Disease (GERD) by GERD Q Questionnaire and by 24 Hour pH Monitoring: A Preliminary Report

Sa1584 Minimal Change Esophagitis by High Definition Endoscopy and I-SCAN Endoscopy in Dyspeptic Patients With or Without Gastroesophareal Reflux Disease (GERD) by GERD Q Questionnaire and by 24 Hour pH Monitoring: A Preliminary Report

Sa1657 Real-Time Detection of Helicobacter pylori by High-Definition Endoscopy is Possible Within the Gastric Corpus

Sa1657 Real-Time Detection of Helicobacter pylori by High-Definition Endoscopy is Possible Within the Gastric Corpus

Su1495 High Definition Endoscopy Increases the Number of Adenomas Detected in the UK Bowel Cancer Screening Population

Adenoma detection and removal is one of the main goals of colonoscopy. Improved adenoma detection has been shown to reduce future risk of colorectal cancer. High definition colonoscopy allows better visualisation of the colonic mucosa and may improve detection of polyps. Previous studies have shown variable results when comparing polyp and adenoma detection between standard definition (SD) and high definition (HD) colonoscopy. The UK bowel cancer screening programme (BCSP) offers colonoscopy to all citizens aged 60-75 years who test positive for faecal occult blood (FOB).

Recognition of Microscopic Colitis at Colonoscopy

Microscopic colitis is a common condition in Canada and is characterized by watery diarrhea with normal endoscopic mucosal appearance using conventional white-light endoscopy. Two types of microscopic colitis are recognized by histological appearance: lymphocytic colitis and collagenous colitis. Recent studies suggest that 10% to 30% of older patients who present with diarrhea and demonstrate normal mucosal appearance at endoscopy have microscopic colitis (1). Increasingly, however, with high-definition endoscopy assisted by postprocessing of images by filter techniques in combination with chromoendoscopy, subtle abnormalities of the mucosa are apparent in patients with microscopic colitis. iScan (Pentax, Japan) is a newly developed postprocessing light filter that enhances details of the mucosal surface, mucosal patterns (i-Scan p designated iScan 1) and vessel architecture (i-Scan v designated iScan 2). i-Scan is a technique designed for differentiating neoplastic from non-neoplastic lesions in the colon. This new digital modality can characterize mucosal patterns of the gastrointestinal mucosa in detail. Subtle abnormalities can, therefore, be recognized as either neoplastic or inflammatory. Hoffman et al (2) have tested the efficacy of high-definition endoscopy alone in comparison with i-Scan or chromoendoscopy with methylene blue (0.1%) in screening for colorectal cancer. They demonstrated that both i-Scan and chromoendoscopy identified more lesions compared with high-definition endoscopy alone. i-Scan was also able to predict neoplasia as precisely as chromoendoscopy, with an accuracy of 89% to 97%. Case Presentation A 50-year-old woman with persistent undiagnosed chronic watery diarrhea underwent colonoscopy, with random biopsies that were negative. Another colonoscopy was performed with iScan + chromoendoscopy with 0.2% indigo carmine to enhance mucosal surfaces and patterns, and to target biopsies in the colon. iScan 1 and iScan 2 showed irregularity of the colonic mucosal pattern, although the mucosa appeared normal with white-light endoscopy. iScan + chromoendoscopy with indigo carmine characterized, in detail, the mucosal pattern as nodularmosaic with a small honeycomb pit-pattern appearance (Figure 1). Such an appearance is characteristic of microscopic colitis. Targeted

Gastric Preparation for Upper Endoscopy

Gastric Preparation for Upper Endoscopy

Improvement in the Adenoma Detection Rate with High Definition Colonoscopes (HD-C)

Purpose: Development of high definition endoscopes has been a recent technological advancement in endoscopic imaging. Whether these improve adenoma detection rates during screening colonoscopies(SC) is not clear. The aim of the study was to compare standard definition colonoscopes(SD-C) and HD-C for: 1. Proportion of subjects with adenomas and number of adenomas detected per subject. 2. Proportion of subjects with advanced adenomas and number of advanced adenomas detected per subject. 3. Proportion of subjects with right sided adenomas and number of right sided adenomas detected per subject. Methods: We conducted a retrospective review of all SC performed at a tertiary referral center during two different time periods by 4 experienced endoscopists with or without a trainee. Between Jan 2005 and Dec 2006, all SC were performed with SD-C (Olympus 140 and 160 series) and were included in the SD-C arm. After HD-C (Olympus 180 series) were acquired by our unit, the older generation colonoscopes were phased out. All SC performed with HD-C between Jan 2008 to Sep 2010 were included in the HD-C arm. Detailed review of the patient records, endoscopy reports and histology reports was conducted. Fisher's exact test, unpaired t test and Wilcoxon rank sum test were used for statistical analysis. Results: A total of 2,015 SC were reviewed; 1056 in SD-C arm and 959 in HDC arm. Mean age was higher in the SD-C arm compared to HD-C arm (60.4 yrs vs 58.5 yrs; p <0.001). There were higher number of males in SD-C arm (98% vs 96%; p = 0.002). 74% subjects in SD-C arm were Caucasians compared to 71% in HD-C arm (p = 0.06). There were no significant differences between the two groups with respect to the inadequacy of bowel prep (p>0.99). The proportion of subjects with adenomas, number of adenomas per subject, proportion of subjects with advanced adenomas, number of advanced adenomas per subject, proportion of subjects with right sided adenomas and right sided adenomas per subject are shown in the Table.Table: No Caption available.Conclusion: 1. HD-C detected a 10% higher number of subjects with adenomas and a 41% higher number of adenomas per subject. 2. HD-C also detected a significantly higher number of advanced adenomas and right sided adenomas. 3. HD-C is a significant advancement in endoscopic imaging that can improve adenoma detection rates and may have a positive impact on the effectiveness of colonoscopy in preventing colorectal cancer. Disclosure: Deepthi Rao - No financial relationship with Olympus. Neil Gupta - No financial relationship with Olympus. Prateek Sharma - Olympus Grant / Research support. Ajay Bansal - No financial relationship with Olympus. Amit Rastogi - Olympus Grant / Research support.

Magnification électronique en endoscopie digestive

Precise endoscopic assessment of gastrointestinal mucosal features is important to detect neoplastic lesions at an early stage. Electronic virtual chromoendoscopy markedly improves capillary pattern contrast and is an in vivo method for visualizing microvessel morphological changes in superficial neoplastic lesions. The scientific basis for this technique is that short wavelength light falls within the haemoglobin absorption band, thereby facilitating clearer visualization of vascular structures and pit pattern. Narrow band imaging (NBI, Olympus), multiband imaging (FICE) and i-scan are real-time, on-demand endoscopic imaging techniques available with high-definition endoscope. Potential indications include both the detection of premalignant lesions and differentiation between neoplastic and nonneoplastic lesions. The ease and readiness of use and the routine availability of virtual chromoendoscopy will probably contribute to its popularity. This does not alleviate the need to better define the role of these endoscopic techniques in daily practice by conducting well-designed prospective studies.

Vision-Based Navigation in Image-Guided Interventions

The trend toward minimally invasive surgical interventions has created new challenges for visualization during surgical procedures. However, at the same time, the introduction of high-definition digital endoscopy offers the opportunity to apply methods from computer vision to provide visualization enhancements such as anatomic reconstruction, surface registration, motion tracking, and augmented reality. This review provides a perspective on this rapidly evolving field. It first introduces the clinical and technical background necessary for developing vision-based algorithms for interventional applications. It then discusses several examples of clinical interventions where computer vision can be applied, including bronchoscopy, rhinoscopy, transnasal skull-base neurosurgery, upper airway interventions, laparoscopy, robotic-assisted surgery, and Natural Orifice Transluminal Endoscopic Surgery (NOTES). It concludes that the currently reported work is only the beginning. As the demand for minimally invasive procedures rises, computer vision in surgery will continue to advance through close interdisciplinary work between interventionists and engineers.

NBI versus hochauflösende Endoskopie in der Diagnostik von Neoplasien bei Colitis ulcerosa

BACKGROUND AND STUDY AIMS: Controversy exists about which colonoscopic technique is most sensitive for the diagnosis of neoplasia in patients with ulcerative colitis. We compared new-generation narrow-band imaging (NBI) to high-definition endoscopy (HDE) for the detection of neoplasia and evaluated NBI for the differentiation of neoplastic from non-neoplastic mucosa. PATIENTS AND METHODS: Randomized crossover trial in which patients with ulcerative colitis under-went both NBI and HDE colonoscopy in random order with at least 3 weeks between the two procedures, which were performed by different endoscopists. Lesions detected during the first examination were left in situ in order to enable detection during the second examination as well. Main outcome measures were (1) neoplasia detection, and (2) diagnostic accuracy of NBI for -differentiating neoplastic from non-neoplastic mucosa by using the Kudo classification and vascular pattern intensity (VPI). RESULTS: Twenty-five patients were randomized to undergo HDE first and 23 to undergo NBI first. Of 16 neoplastic lesions, 11 (69 %) were detected by HDE and 13 (81 %) by NBI (P = 0.727). Of 11 patients with neoplasia, 9 (82 %) were diagnosed by HDE and 8 (73 %) by NBI (P = 1.0). The sensitivity, specificity, and accuracy of the Kudo classification were 76 %, 66 % and 67 %. Corresponding figures for VPI were 80 %, 72 % and 73 %. CONCLUSION: NBI does not improve the detection of neoplasia in patients with ulcerative colitis compared to HDE. In addition, NBI proves unsatisfactory for differentiating neoplastic from non-neoplastic mucosa.

Differences of image enhancement in image-enhanced endoscopy: narrow band imaging versus flexible spectral imaging color enhancement

Narrow band imaging (NBI) can emphasize images of the surface microvasculature of lesions, because the central wavelengths of the NBI filter are 415 and 540nm and these wavelengths are well absorbed by hemoglobin. Flexible spectral imaging color enhancement (FICE) increases the contrast in depictions of mucosal lesions. However, quantitative evaluation of the image enhancement shown by NBI and FICE has not been reported. The aim of this study was to measure and compare the degrees of image enhancement in NBI and FICE. We compared the visibility of human blood diluted with distilled water between that shown by white-light imaging (WLI) and that shown by NBI or FICE. One milliliter of human blood was plated onto a 12-well transparent plastic plate to set up doubling dilutions, from 1/2 to 1/2(23). High-definition endoscopes were used for each imaging method. A total of 11 endoscopists independently evaluated the visibility of the diluted blood. The median dilution was defined as the limit of visibility in each image. NBI enabled clearer visualization of the presence of blood compared with conventional WLI. NBI recognized blood contamination up to a 1/2(14) dilution, whereas conventional WLI recognized blood contamination up to a 1/2(11) dilution. In contrast, FICE did not improve the visualization of diluted blood and recognized blood contamination up to a 1/2(10) dilution. NBI more effectively enhanced images of diluted blood compared to conventional WLI, while FICE did not improve the visualization of the diluted blood. These data suggest the usefulness of NBI for the early detection of gastrointestinal neoplasia, which is accompanied by abundant neovascularization.

Asian minimal-change esophagitis in the era of high-definition endoscopy

Asian minimal-change esophagitis in the era of high-definition endoscopy