Real-time Optical Diagnosis Research Articles

Effectiveness of Dual-Focus Magnification on Confidence Levels in Optical Diagnosis of Small Colorectal Polyps.

Background and objectives Achieving accurate real-time optical diagnoses of colorectal polyps with high-confidence predictions is crucial for appropriate decision-making in daily practice. The dual-focus (DF) magnification mode helps endoscopists scrutinize subtle features of polyp surfaces and vessel patterns. This prospective study aimed to evaluate the impact of DF imaging on enhancing the rate of high-confidence narrow-band imaging (NBI)-based optical diagnosis. Methods Consecutive adult patients who underwent colonoscopy and had small colorectal polyps (<10 mm) were enrolled between September 2022 and May 2023. The optical diagnosis of each polyp was evaluated during colonoscopy in two stages by the same endoscopist, utilizing NBI with DF magnification (NDB-DF). A confidence level was assigned to each prediction. High confidence was indicated by clinical judgment when a polyp exhibited distinctive features associated solely with one histological subtype and lacked characteristics of any other subtype. All procedures were carried out with a prototype 190 series Exera III NBI system (Olympus Corporation, Tokyo, Japan) with DFmagnification. Results The study included 413 patients with 623 polyps, comprising 483 ≤ 5 mm and 140 measuring 6-9 mm. The majority were low-grade adenomas (343 lesions), with 17 identified as high-grade adenomas, and none characterized as deep submucosal invasive carcinomas. NBI-DF significantly improved the rate of high-confidence optical diagnoses compared to NBI for both ≤ 5 mm polyps (93.1% vs. 87.5%, p < 0.0001) and 6-9 mm polyps (97.9% vs. 94.2%, p = 0.03). Furthermore, DF significantly facilitated the assessment of microvessel and surface pattern criteria (p < 0.01). Conclusion DF magnification markedly enhanced the rate of high-confidence NBI-based optical predictions for small colorectal polyps. This technique demonstrates the potential for improving the diagnostic yield in real-time optical diagnosis of colorectal polyps in the Vietnamese setting.

First report from the International Evaluation of Endoscopic classification Japan NBI Expert Team: International multicenter web trial.

Narrow-band imaging (NBI) contributes to real-time optical diagnosis and classification of colorectal lesions. The Japan NBI Expert Team (JNET) was introduced in 2011. The aim of this study was to explore the diagnostic accuracy of JNET when applied by European and Japanese endoscopists not familiar with this classification. This study was conducted by 36 European Society of Gastrointestinal Endoscopy (ESGE) and 49 Japan Gastroenterological Endoscopy Society (JGES) non-JNET endoscopists using still images of 150 lesions. For each lesion, nonmagnified white-light, nonmagnified NBI, and magnified NBI images were presented. In the magnified NBI, the evaluation area was designated by region of interest (ROI). The endoscopists scored histological prediction for each lesion. In ESGE members, the sensitivity, specificity, and accuracy were respectively 73.3%, 94.7%, and 93.0% for JNET Type 1; 53.0%, 64.9%, and 62.1% for Type 2A; 43.9%, 67.7%, and 55.1% for Type 2B; and 38.1%, 93.7%, and 85.1% for Type 3. When Type 2B and 3 were considered as one category of cancer, the sensitivity, specificity, and accuracy for differentiating high-grade dysplasia and cancer from the others were 59.9%, 72.5%, and 63.8%, respectively. These trends were the same for JGES endoscopists. The diagnostic accuracy of the JNET classification was similar between ESGE and JGES and considered to be sufficient for JNET Type 1. On the other hand, the accuracy for Types 2 and 3 is not sufficient; however, JNET 2B lesions should be resected en bloc due to the risk of cancers and JNET 3 can be treated by surgery due to its high specificity.

Optical diagnosis by near-focus versus normal-focus narrow band imaging colonoscopy in colorectal polyps based on combined NICE and WASP classification: a randomized controlled trial.

Background/AimsNarrow Band Imaging (NBI) International Colorectal Endoscopic (NICE) and Workgroup Serrated Polyps and Polyposis (WASP) classifications were developed for optical diagnosis of neoplastic and sessile serrated polyps, respectively. Near-focus NBI with NICE combined with WASP criteria for optical diagnosis of colonic polyps has not yet been evaluated. We aimed to compare the accuracy of near-focus NBI (group A) with normal-focus NBI (group B) in real-time optical diagnosis of colorectal polyps using combined NICE and WASP criteria. MethodsAmong 362 patients, 118 with 227 polyps were recruited. Groups A and B included 62 patients with 130 polyps (three lost polyps) and 56 patients with 106 polyps (six lost polyps), respectively. Optical diagnoses were compared with pathological reports. ResultsThe accuracy of optical diagnosis of neoplastic polyps in groups A and B was not significantly different (76% vs. 71%, p=0.52). WASP criteria provided all false positive diagnoses of sessile polyps as serrated polyps in 31 (16.2%) patients. ConclusionsNear-focus NBI was not superior to normal-focus NBI in optical diagnostics of neoplastic polyps using NICE criteria. In our study, WASP classification yielded all false positives in the diagnosis of sessile serrated adenomas/polyps. Routine real-life optical diagnosis of polyps is still unadvisable.

Artificial intelligence for disease diagnosis: the criterion standard challenge

Artificial intelligence for disease diagnosis: the criterion standard challenge

Advanced mucosal imaging in colonoscopy: technical details and clinical applications

Over the past decades, the significant development in endoscopic imaging has revolutionized digestive endoscopy. Real-time optical diagnosis has become possible using different tools and techniques (dye-based and virtual chromoendoscopy) such as narrow band imaging, flexible spectral imaging color enhancement, i-Scan, blue-laser imaging and linked-color imaging. Polyp detection and characterization, and prediction of depth of invasion of colorectal cancers have improved remarkably. Confocal laser endomicroscopy and endocytoscopy have allowed the evaluation of lesions on a cellular level. Not far from the horizon are newer technological innovations such as artificial intelligence and texture and color enhancement imaging that are now being studied for their potential to further improve mucosal visualization, optical diagnosis and virtual histology. This review gives an overview of image-enhanced endoscopy (IEE) and discusses its clinical applications and future directions in the lower gastrointestinal (GI) tract.

A79 CLINICAL VALIDATION OF THE SIMPLE CLASSIFICATION FOR OPTICAL DIAGNOSIS OF DIMINUTIVE AND SMALL COLORECTAL POLYPS

Abstract Background Image enhanced endoscopy (IEE) allows for real-time optical diagnosis of colorectal polyps in order to replace histopathology. A novel classification system (SIMPLE classification) has recently been developed for optical diagnosis when using the novel Pentax Optivista IEE platform. Aims The aim of this study was to evaluate the SIMPLE classification for optical polyp diagnosis in a prospective clinical study. Methods Patients undergoing screening, diagnostic or surveillance colonoscopies were enrolled in the study. All colorectal polyps 1-10mm found underwent optical polyp diagnosis using the SIMPLE classification with either iScan or Optivista for image-enhanced endoscopy (IEE). Polyps were resected as per standard care and sent for histopathology analysis. Optical diagnosis and surveillance intervals were calculated based on SIMPLE criteria and compared to pathology-based results as reference. Primary outcome was the agreement of the surveillance intervals based on the SIMPLE classification with pathology-based surveillance intervals for 1-5mm colorectal polyps. Secondary outcomes included negative predictive value (NPV) for rectosigmoid adenoma, percentage of pathology avoided, percentage of post-colonoscopy immediate recommendations, and surveillance interval agreement, rectosigmoid NPV for 1-10mm polyps. Results 399 patients (mean age: 62.4, 55.6% female) with 278 diminutive and 364 small polyps were evaluated in the study cohort. For ≤5mm polyps, agreement with pathology-based surveillance intervals was 93.5% [95% CI 91.1–95.9] (shorter: 4.5% [95% CI 2.5–6.5]; longer: 1.8% [95% CI 0.5–3.0]). NPV for rectosigmoid adenomatous polyps (including SSA) was 85.5% [95% CI 77.6–93.4]. Using Optical diagnosis and the SIMPLE classification, pathology analysis could be avoided in 61.5% [95% CI 56.9–66.2] of polyps and post-colonoscopy immediate surveillance interval recommendation could be given in 70.9% [95% CI 66.5–75.4] of patients. For ≤10mm polyps, agreement with pathology-based surveillance intervals was 92.2% [95% CI 89.6–94.9] (shorter: 5.5% [95% CI 3.3–7.8]; longer: 2.3% [95% CI 0.8–3.7]). NPV for rectosigmoid adenomatous polyps (including SSA) was 83.7% [95% CI 75.9–91.5]. Conclusions The first clinical validation study using the SIMPLE classification in combination with Optivista or iScan IEE showed a high (≥90%) surveillance interval agreement compared to pathology. More than 60% of pathology could be avoided, and most patients could be given immediate surveillance intervals when using IEE in combination with the SIMPLE classification. Funding Agencies NonePentax

Advanced imaging for detection and differentiation of colorectal neoplasia: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2019.

1: ESGE suggests that high definition endoscopy, and dye or virtual chromoendoscopy, as well as add-on devices, can be used in average risk patients to increase the endoscopist's adenoma detection rate. However, their routine use must be balanced against costs and practical considerations.Weak recommendation, high quality evidence. 2: ESGE recommends the routine use of high definition systems in individuals with Lynch syndrome.Strong recommendation, high quality evidence. 3: ESGE recommends the routine use, with targeted biopsies, of dye-based pancolonic chromoendoscopy or virtual chromoendoscopy for neoplasia surveillance in patients with long-standing colitis.Strong recommendation, moderate quality evidence. 4: ESGE suggests that virtual chromoendoscopy and dye-based chromoendoscopy can be used, under strictly controlled conditions, for real-time optical diagnosis of diminutive (≤ 5 mm) colorectal polyps and can replace histopathological diagnosis. The optical diagnosis has to be reported using validated scales, must be adequately photodocumented, and can be performed only by experienced endoscopists who are adequately trained, as defined in the ESGE curriculum, and audited.Weak recommendation, high quality evidence. 5: ESGE recommends the use of high definition white-light endoscopy in combination with (virtual) chromoendoscopy to predict the presence and depth of any submucosal invasion in nonpedunculated colorectal polyps prior to any treatment. Strong recommendation, moderate quality evidence. 6: ESGE recommends the use of virtual or dye-based chromoendoscopy in addition to white-light endoscopy for the detection of residual neoplasia at a piecemeal polypectomy scar site. Strong recommendation, moderate quality evidence. 7: ESGE suggests the possible incorporation of computer-aided diagnosis (detection and characterization of lesions) to colonoscopy, if acceptable and reproducible accuracy for colorectal neoplasia is demonstrated in high quality multicenter in vivo clinical studies. Possible significant risks with implementation, specifically endoscopist deskilling and over-reliance on artificial intelligence, unrepresentative training datasets, and hacking, need to be considered. Weak recommendation, low quality evidence.

Improved Real-Time Optical Diagnosis of Colorectal Polyps Following a Comprehensive Training Program

The optimal training method for endoscopic characterization of colorectal polyps using narrow-band imaging is uncertain, and sessile serrated lesions (SSLs) optical diagnosis data are lacking. We aimed to evaluate a comprehensive training program for real-time optical diagnosis of colorectal polyps, including SSLs. We performed a single-institution prospective study of 15 endoscopists trained with the Workgroup Serrated Polyps and Polyposis classification system. After the first phase of in vivo optical diagnosis, their performances were evaluated. After re-education for insufficient competency, they began the second phase. The learning curves and performance on 2 preservation and incorporation of valuable endoscopic innovations benchmarks were assessed. A total of 7294 polyps, including 486 SSLs, were diagnosed in real-time. The overall accuracy improved from 73.5% in the first phase to 77.1% in the second. The accuracy with high confidence was 79.4% and 85.1% in the first and second phases, respectively. In the first and second phases, the negative predictive values for diminutive neoplastic polyps were 82.1% and 92.5%, respectively, and concordances of the surveillance intervals were 80.7% and 89.7%, respectively. Eight endoscopists achieved the preservation and incorporation of valuable endoscopic innovations benchmarks after the second phase compared with none after the first. In contrast, the high confidence rate decreased from 74.6% to 70.2% as training progressed. A comprehensive training program for real-time optical diagnosis significantly improved performance and reduced individual variability in less-experienced endoscopists. ClinicalTrials.gov no: NCT02516748.

Preparation of multiresponsive nanogels and their controlled release properties

Multiresponsive nanogels, which are sensitive to pH/temperature/glucose concentration have been synthesized by using N,N-diethylacrylamide (DEA) and 4-vinylphenylboronic acid (VPBA) as reaction monomer. The influence of the VPBA/DEA feeding ratio and emulsifier concentration on the as-prepared nanogel’s size and size distribution was investigated. Under the optimized condition, the diameter of the as-prepared P(DEA-co-VPBA) nanogel was 186.9 nm with excellent monodispersity (PDI 0.005); its entrapment efficiency reached 88.67% and loading efficiency of insulin reached 17.73%. The release rate of insulin loaded in the P(DEA-co-VPBA) nanogels could be adjusted by glucose concentration, which could adjust and control the blood glucose concentration in a stable concentration range intelligently. The multiresponsive nanogels could potentially be used in the fields of self-regulated drug delivery systems, real-time optical diagnosis, and monitoring of the response to treatment.

Real-Time Optical Diagnosis of Colorectal Polyps in the Routine Clinical Practice Using the NICE and WASP Classifications in a Nonacademic Setting

Background: Narrow-band imaging (NBI) allows “in vivo” classification of colorectal polyps. Objectives: We evaluated the optical diagnosis by nonexpert community-based endoscopists in routine clinical practice, the impact of training, and whether the endoscopists could achieve the threshold for the “do not resect” policy. Methods: This was an observational study performed in two periods (P1 and P2). Endoscopists had no prior experience in NBI in P1 and applied the technique on a daily basis for 1 year before participation in P2. Lesions were classified by applying the NBI International Colorectal Endoscopic (NICE) and Workgroup serrAted polypS and Polyposis (WASP) classifications, simultaneously. Results: A total of 290 polyps were analyzed. The overall accuracy of optical diagnosis was 0.75 (95% CI 0.68–0.81) in P1, with an increase to 0.82 (95% CI 0.73–0.89) in P2 (p = 0.260). The accuracy of the NICE/WASP classifications to differentiate adenomatous from nonadenomatous histology was 0.78 (95% CI 0.72–0.84) in P1 and 0.86 (95% CI 0.77–0.92) in P2 (p = 0.164); assignments made with a high confidence level achieved statistical significance (13% improvement, 95% CI 3–22%; p = 0.022). The negative predictive value for adenomatous histology of diminutive rectosigmoid polyps was 81% (95% CI 64–93%) and 80% (95% CI 59–93%) in P1 and P2, respectively. Conclusions: Nonexpert endoscopists achieved moderate accuracy for real-time optical diagnosis of colorectal lesions with the NICE/WASP classifications. The overall performance of the endoscopists improved after sustained use of optical diagnosis, but did not achieve the standards for the implementation of the “do not resect” strategy.

Multicentre prospective evaluation of real-time optical diagnosis of T1 colorectal cancer in large non-pedunculated colorectal polyps using narrow band imaging (the OPTICAL study)

ObjectiveThis study evaluated the preresection accuracy of optical diagnosis of T1 colorectal cancer (CRC) in large non-pedunculated colorectal polyps (LNPCPs).DesignIn this multicentre prospective study, endoscopists predicted the histology during colonoscopy...

Virtual chromoendoscopy for the real-time assessment of colorectal polyps in vivo: a systematic review and economic evaluation.

Current clinical practice is to remove a colorectal polyp detected during colonoscopy and determine whether it is an adenoma or hyperplastic by histopathology. Identifying adenomas is important because they may eventually become cancerous if untreated, whereas hyperplastic polyps do not usually develop into cancer, and a surveillance interval is set based on the number and size of adenomas found. Virtual chromoendoscopy (VCE) (an electronic endoscopic imaging technique) could be used by the endoscopist under strictly controlled conditions for real-time optical diagnosis of diminutive (≤ 5 mm) colorectal polyps to replace histopathological diagnosis. To assess the clinical effectiveness and cost-effectiveness of the VCE technologies narrow-band imaging (NBI), flexible spectral imaging colour enhancement (FICE) and i-scan for the characterisation and management of diminutive (≤ 5 mm) colorectal polyps using high-definition (HD) systems without magnification. Systematic review and economic analysis. People undergoing colonoscopy for screening or surveillance or to investigate symptoms suggestive of colorectal cancer. NBI, FICE and i-scan. Diagnostic accuracy, recommended surveillance intervals, health-related quality of life (HRQoL), adverse effects, incidence of colorectal cancer, mortality and cost-effectiveness of VCE compared with histopathology. Electronic bibliographic databases including MEDLINE, EMBASE, The Cochrane Library and Database of Abstracts of Reviews of Effects were searched for published English-language studies from inception to June 2016. Bibliographies of related papers, systematic reviews and company information were screened and experts were contacted to identify additional evidence. Systematic reviews of test accuracy and economic evaluations were undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Meta-analyses were conducted, where possible, to inform the independent economic model. A cost-utility decision-analytic model was developed to estimate the cost-effectiveness of VCE compared with histopathology. The model used a decision tree for patients undergoing endoscopy, combined with estimates of long-term outcomes (e.g. incidence of colorectal cancer and subsequent morbidity and mortality) derived from University of Sheffield School of Health and Related Research's bowel cancer screening model. The model took a NHS perspective, with costs and benefits discounted at 3.5% over a lifetime horizon. There were limitations in the data on the distribution of adenomas across risk categories and recurrence rates post polypectomy. Thirty test accuracy studies were included: 24 for NBI, five for i-scan and three for FICE (two studies assessed two interventions). Polyp assessments made with high confidence were associated with higher sensitivity and endoscopists experienced in VCE achieved better results than those without experience. Two economic evaluations were included. NBI, i-scan and FICE are cost-saving strategies compared with histopathology and the number of quality-adjusted life-years gained was similar for histopathology and VCE. The correct surveillance interval would be given to 95% of patients with NBI, 94% of patients with FICE and 97% of patients with i-scan. Limited evidence was available for i-scan and FICE and there was heterogeneity among the NBI studies. There is a lack of data on longer-term health outcomes of patients undergoing VCE for assessment of diminutive colorectal polyps. VCE technologies, using HD systems without magnification, could potentially be used for the real-time assessment of diminutive colorectal polyps, if endoscopists have adequate experience and training. Future research priorities include head-to-head randomised controlled trials of all three VCE technologies; more research on the diagnostic accuracy of FICE and i-scan (when used without magnification); further studies evaluating the impact of endoscopist experience and training on outcomes; studies measuring adverse effects, HRQoL and anxiety; and longitudinal data on colorectal cancer incidence, HRQoL and mortality. This study is registered as PROSPERO CRD42016037767. The National Institute for Health Research Health Technology Assessment programme.

Optical Diagnosis of Sessile Serrated Polyps: Bottleneck for the Optical Diagnosis Paradigm?

Optical diagnosis of diminutive (1 to 5 mm) polyps could result in a more cost-effective colonoscopy practice. Previous optical diagnosis studies did not incorporate the differentiation of sessile serrated polyps (SSPs). This study aimed to evaluate the impact of optical diagnosis of diminutive SSPs on the overall performance of endoscopic polyp differentiation in daily colonoscopy practice. Endoscopy data were prospectively collected between 2011 and 2014 in a colonoscopy center. Each endoscopist reported a real-time optical diagnosis (SSP, adenoma or hyperplastic polyp) for all lesions in a structured colonoscopy reporting system, using narrow band imaging at their discretion. Study outcomes were accuracy of optical diagnosis, surveillance interval agreement and negative predictive value for diminutive rectosigmoid neoplastic histology based on the optical diagnosis of diminutive polyps compared to histopathology. Of 2853 removed diminutive polyps, 202 (7.1%) were histologically proven SSPs. Optical diagnosis of diminutive SSPs was accurate in 24.4%. Diminutive SSPs determined 6.9% of postpolypectomy surveillance assignments. Inaccurate optical diagnosis of diminutive SSPs led to lower surveillance interval agreement (78.1% vs. 53.3%, P<0.01) and pooled negative predictive value per polyp (84.3% vs. 50.0%; P<0.01) in patients with diminutive SSPs when compared to patients without diminutive SSPs. Accurate endoscopic identification of diminutive SSPs improved from 0% in 2011 to 47% in 2014 (P=0.02). Endoscopic characterization of diminutive SSPs is difficult, impairing overall performance of optical diagnosis in patients with diminutive SSPs. Future optical diagnosis studies should use validated trainings and classification algorithms that include differentiation of SSPs.

Narrow-band imaging vs. high definition white light for optical diagnosis of small colorectal polyps: a randomized multicenter trial.

The aim of the study was to compare the latest narrow-band imaging (NBI) device with high-definition white light (HDWL) endoscopy for accuracy of real-time optical diagnosis of small colorectal polyps. We conducted a randomized, prospective, multicenter trial at three study sites in Germany. In the NBI arm, endoscopists used NBI for the prediction of polyp pathology on the basis of the NBI International Colorectal Endoscopic classification. In the HDWL arm, NBI was not used for optical classification of polyp histology. The primary outcome was accuracy of optical diagnoses (neoplastic vs. non-neoplastic) in small polyps measuring < 10 mm. Secondary end points included sensitivity and negative predictive value (NPV). A total of 380 patients were randomized 1:1 to either the NBI or HDWL arm. A total of 421 polyps measuring < 10 mm were detected (55.8 % neoplastic, 44.2 % non-neoplastic). Accuracy, sensitivity, and NPV were 73.7 %, 82.4 %, and 75.5 %, respectively, in the NBI arm and 79.2 %, 79.8 %, and 73.4 %, respectively, in the HDWL arm (P = 0.225, P = 0.667, P = 0.765). More polyps were assessed with high confidence in the HDWL arm (82.6 %) than in the NBI arm (73.7 %; P = 0.038). The NPV of the prediction of neoplastic histology in diminutive polyps (≤ 5 mm) rated with high confidence was 90.3 % in the NBI arm. We detected significant differences between the participating study sites in the performance data of predictions. The levels of accuracy for real-time prediction of polyp histology (< 10 mm) did not differ between NBI and HDWL for optical diagnosis. Variation in the performance of optical diagnosis was apparent between study centers. ClinicalTrials.gov (NCT02009774).

Raman spectroscopy for early real-time endoscopic optical diagnosis based on biochemical changes during the carcinogenesis of Barrett's esophagus.

Raman spectroscopy is a spectroscopic technique based on the inelastic scattering of monochromatic light that represents the molecular composition of the interrogated volume to provide a direct molecular fingerprint. Several investigations have revealed that confocal Raman spectroscopy can differentiate non-dysplastic Barrett's esophagus from esophageal high-grade dysplasia and adenocarcinoma with high sensitivity and specificity. An automated on-line Raman spectral diagnostic system has made it possible to use Raman spectroscopy to guide accurate target biopsy instead of multiple random forceps-biopsies, this novel system is expected to improve in vivo precancerous diagnosis and tissue characterization of Barrett's esophagus.

Light-NBI to identify high-risk phenotypes for gastric adenocarcinoma: do we still need biopsies?

Objective Early diagnosis of gastric cancer may be achieved through surveillance of patients with extensive gastric intestinal metaplasia (eGIM). However, diagnosis of eGIM generally implies histology. We aimed at determining the accuracy of high-resolution endoscopy with light-narrow band imaging (NBI) to assess the presence of eGIM on a per-patient basis. Material and methods Prospective cohort of 60 patients divided into two groups: derivation cohort (n = 25) to evaluate the reliability and validity, and a real-time validation group (n = 35). In the derivation group, six endoscopists with two levels of expertise were asked to estimate the grade of GIM based in endoscopic images (white light endoscopy, light-NBI and amplification/near focus). In the real-time validation set, experienced endoscopists were asked to similarly record their real-time optical diagnosis. Histology was then considered as the gold standard. Results In the derivation group diagnosis accuracy was 60% with WLE (non-expert 59% vs. 61% experts), increasing to 73% after NBI magnification (non-expert 63% vs. 83% expert, p < 0.05). Moreover, proportion of agreement with histology was 83%, with a correct diagnosis of eGIM in 87% for experienced observers. In the real-time group experts obtained 89% global diagnostic accuracy correctly identifying 91% of the eGIM. The sensitivity, specificity, LR + and LR- of real-time endoscopic diagnosis of eGIM was 0.92 (CI95%:0.67–0.99), 0.96 (0.79–0.99), 21.1 (3.08–144) and 0.09 (0.013–0.57). Conclusion For the first time the reliability of high-resolution endoscopy with light-NBI for extension of GIM is described. Our results suggest that more than 90% of individuals at risk could be identified without the need for biopsies, simplifying the current recommendations.

Narrow-band imaging in the prediction of surveillance intervals after polypectomy in community practice.

It has been proposed that the use of narrow-band imaging (NBI) for real-time histological assessment to determine postpolypectomy surveillance intervals is a cost-effective approach to the management of diminutive polyps. However, significant discrepancies in NBI performance have been observed among endoscopists; hence, professional societies recommend training, monitoring, and auditing. The aim of the present study was to evaluate the performance of real-time optical diagnosis for diminutive polyps after the inclusion of this approach in an internal quality assurance program, in order to assess its applicability in clinical practice Patients and methods: Four endoscopists attended periodic training sessions on NBI assessment of polyp histology before and during the study. Performance was audited and periodic feedback was provided. The accuracy of high-confidence NBI evaluation for polyps ≤ 5 mm in predicting surveillance intervals according to the European and US guidelines, and the negative predictive value (NPV) for adenoma in the rectosigmoid were calculated and compared with recommended thresholds (90 % agreement and 90 % NPV, respectively). Overall, 284 outpatients (mean age 61.3 ± 18.2 years; 63 % males) were enrolled. A total of 656 polyps were detected, 465 of which (70.9 %) were diminutive (70.5 % adenomas). Sensitivity, specificity, positive and negative predictive values, and accuracy of high-confidence NBI predictions for adenoma in diminutive lesions were 95.3 %, 83.5 %, 93.5 %, 87.6 %, and 91.9 %, respectively. High-confidence characterization of diminutive polyps predicted the correct surveillance interval in 95.8 % and 93.3 % of cases according to European and American guidelines, respectively. NPV for adenoma in the rectosigmoid was 91.3 % For community settings in which endoscopists are adequately trained and performance is periodically audited, real-time optical diagnosis for diminutive polyps is sufficiently accurate to avoid postpolypectomy histological examination of resected lesions, or to leave rectosigmoid hyperplastic polyps in place. Trial registered at ClinicalTrials.gov (NCT02196402).

The addition of high magnifying endoscopy improves rates of high confidence optical diagnosis of colorectal polyps.

Background and study aims: The real-time optical diagnosis of colorectal polyps with high confidence predictions can achieve high levels of accuracy. Increasing the rates of high confidence optical diagnosis can improve the clinical application of real-time optical diagnosis in routine practice. The primary aim of this prospective study was to evaluate whether high magnifying endoscopy improves the rates of high confidence narrow-band imaging (NBI) – based optical diagnosis for differentiating between neoplastic and non-neoplastic colorectal lesions according to the NBI international colorectal endoscopic (NICE) classification. Patients and methods: Consecutive adult patients undergoing colonoscopy with a high magnifying (maximum, × 80) colonoscope between April and August 2012 were recruited. The optical diagnosis for each polyp was evaluated during colonoscopy in two consecutive stages by the same endoscopist, who first used NBI with non-magnifying endoscopy (NBI-NME), then NBI with magnifying endoscopy (NBI-ME). A level of confidence was assigned to each prediction. Results: The analysis included 124 patients (mean age, 56.4 years; male-to-female ratio, 72:52) with 248 polyps smaller than 10 mm. Of the 248 polyps, 210 were 1 to 5 mm in size and 38 were 6 to 9 mm in size; 77 polyps were hyperplastic, 4 were sessile serrated adenomas/polyps, 160 were low grade adenomas, 5 were high grade adenomas, and 2 were deep submucosal invasive carcinomas. The rate of high confidence optical diagnosis when NBI-ME was used was significantly higher than the rate when NBI-NME was used for diminutive (1 – 5 mm) polyps (92.9 % vs 79.5 %, P < 0.001) and for small (6 – 9 mm) polyps (94.7 % vs 84.2 %, P = 0.048). Conclusion: High magnifying endoscopy significantly improved the rates of high confidence NBI-based optical diagnosis of diminutive and small colorectal polyps.Study registration: UMIN 000007608

Real-time optical diagnosis for diminutive colorectal polyps using narrow-band imaging: the VALID randomised clinical trial

BackgroundDiminutive (≤5 mm) colorectal polyps are common, and overwhelmingly benign. Routinely, after polypectomy, they are examined pathologically to determine the surveillance intervals. Advances in equipment and techniques, such as narrow-band...

Correction: Real-Time Optical Diagnosis of the Rat Brain Exposed to a Laser-Induced Shock Wave: Observation of Spreading Depolarization, Vasoconstriction and Hypoxemia-Oligemia

Correction: Real-Time Optical Diagnosis of the Rat Brain Exposed to a Laser-Induced Shock Wave: Observation of Spreading Depolarization, Vasoconstriction and Hypoxemia-Oligemia