Electronic Virtual Chromoendoscopy Research Articles

New endoscopic tools in inflammatory bowel disease.

Endoscopic remission is now considered the ultimate long-term goal for treating inflammatory bowel disease (IBD). Recent advances in endoscopic techniques have progressively added new tools to the armamentarium of endoscopists for a deeper assessment and characterisation of the intestinal mucosa. Virtual Electronic chromoendoscopy is widely available in the endoscopic units, leading to a more accurate evaluation of the vascular and mucosal architecture of the colon, reducing the gap with histology, which is considered a favourable long-term measure. In addition, advanced, sophisticated techniques such as endocytoscope and confocal laser endomicroscopy provide insights into individualised and personalised IBD therapy. Finally, high expectations are placed on the advent of Artificial Intelligence (AI) with promising applications that have the potential to revolutionise IBD diagnosis and management. Here, we discuss state-of-the-art of endoscopic techniques and their applicability to accurate assess endoscopic and histological remission, predict response to therapy and detect, characterise and guide treatment of colonic dysplastic lesions. We are seeing the dawn of a new era wherein the applications of these new endoscopic tools, hand in hand with AI, offer the most incredible opportunity to deliver precision medicine to patients with IBD.

External validation of the Paddington International Virtual Electronic ChromoendoScopy ScOre as a good endoscopic score to define mucosal healing and predict long‐term clinical outcomes in ulcerative colitis

To define endoscopic and histological remission in ulcerative colitis (UC) accurately, several scoring systems have been established. A novel virtual electronic chromoendoscopy score, the Paddington International Virtual ChromoendoScopy ScOre (PICaSSO), was developed, validated, and reproduced to assess inflammation grade and predict patient prognosis. We externally verified and validated the clinical value of PICaSSO in UC patients. This prospective study enrolled 63 UC patients. The Mayo endoscopic score (MES), UC Endoscopic Index of Severity (UCEIS), and PICaSSO were adopted for endoscopic evaluation. All biopsy samples were scored using the Robarts histological index (RHI), Nancy histological index (NHI), and "Extent, Chronicity, Activity, Plusadditional findings" (ECAP) score. Patients with an endoscopic MES of 0-1 at baseline were followed up during a median time of 23.5 months. PICaSSO wasstrongly correlated with other endoscopic and histological scoring systems. PICaSSO ≤3 had advantages in assessing histological remission (HR), with the highest accuracy of 88.9% for ECAP-HR. Relapse-free survival rates were significantly different between patients with MES 0 and MES 1 and patients with PICaSSO ≤3 and >3 (P=0.010 and 0.018, respectively). PICaSSO was externally validated with strong correlations with other endoscopic and histological scoring systems in UC, and PICaSSO-ER might potentially predict a better long-term clinical outcome in UC patients.

Reproducibility of the electronic chromoendoscopy PICaSSO score (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis using multiple endoscopic platforms: a prospective multicenter international study (with video)

Endoscopic and histologic remission (HR) are key therapeutic targets in the management of ulcerative colitis (UC). The aim of this study was to evaluate the reproducibility of the Paddington International virtual ChromoendoScopy ScOre (PICaSSO), a virtual chromoendoscopy score originally validated by use of the iSCAN platform, with the narrow-band imaging (NBI), linked-color imaging (LCI), and blue-laser imaging (BLI) platforms. We evaluated endoscopic activity using the Mayo Endoscopic Score (MES), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and PICaSSO in 159 UC patients (78 NBI and 81 BLI/LCI) who underwent colonoscopy in 2 tertiary referral centers. HR was defined by the Robarts Histopathology Index (RHI) and the Nancy Histologic Index (NHI). Receiver operating characteristic curves were plotted to evaluate endoscopic scores for the prediction of HR. Intraclass correlation coefficients (ICC) between endoscopists were evaluated. PICaSSO had an ICC of 0.825 when the NBI and BLI/LCI cohorts were combined, higher than MES and UCEIS. The correlation between PICaSSO and RHI and NHI was 0.83 and 0.79 in the NBI cohort and between 0.63 and 0.65 in LCI/BLI. In the NBI cohort, the accuracy of MES, UCEIS, and PICaSSO was 0.936, 0.897, and 0.808 for HR measured by RHI and 0.897, 0.885, and 0.821 by NHI, respectively. In the BLI/LCI cohort, the accuracy of MES, UCEIS, LCI PICaSSO and BLI PICaSSO was 0.765, 0.778, 0.827, and 0.79 to predict HR with RHI and NHI, respectively. The PICaSSO score can be consistently and accurately reproduced with NBI and LCI/BLI and therefore can be applied to all virtual electronic chromoendoscopy platforms.

DOP18 Advanced optical diagnosis technology for assessment of endoscopic and histological remission in Ulcerative Colitis: A systematic review and meta-analysis

Abstract Background Advanced endoscopic technologies led to significant progress in the definition of endoscopic remission of ulcerative colitis (UC), and correlate better with histological changes, compared to standard endoscopy. However, whilst studies have assessed the diagnostic accuracy of endoscope technologies individually, there is current limited data comparing between technologies. As such, we aimed to compare the correlations between endoscopy and histology disease activity scores across endoscope technologies Methods We searched PubMed and Embase in January 2021 for eligible studies reporting the correlation between endoscopy and histology activity scores in UC. Studies were grouped by endoscope technology as standard-definition white light (SD-WLE), high-definition white light (HD-WLE), or electronic virtual chromoendoscopy (VCE), and comparisons made between these groups Results A total of N=27 studies were identified, of which N=12 were included in a meta-analysis of correlations between endoscopic and histological activity scores. Combining these returned a pooled correlation coefficient (rho) for the SD-WLE group of 0.61, which did not differ significantly from HD-WLE (rho: 0.79, p=0.140) or VCE (rho: 0.70, p=0.471) [Fig 1a]. In addition, N=4 studies reported the accuracy of endoscopic activity scores on WLE and VCE to diagnose histological remission. Pooling these found significantly higher accuracy for VCE, compared to WLE (risk ratio: 1.13, 95% CI: 1.07–1.19, p<0.001).[Fig 1b] Conclusion Activity scores assessed using endoscopy are strongly correlated with activity on histology. VCE appears to have better accuracy for the diagnosis of histological remission in UC, compared to WLE.

Advanced technology for assessment of endoscopic and histological activity in ulcerative colitis: a systematic review and meta-analysis.

Background:Advanced endoscopic technologies led to significant progress in the definition of endoscopic remission of ulcerative colitis (UC) and correlate better with histological changes, compared with standard endoscopy. However, while studies have assessed the diagnostic accuracy of endoscope technologies individually, there are currently limited data comparing between technologies. As such, the aim of this systematic review was to pool data from the existing literature and compare the correlations between endoscopy and histologic disease activity scores across endoscope technologies.Methods:We searched PubMed and Embase until February 2021 for eligible studies reporting the correlation between endoscopy and histology activity scores in UC. Studies were grouped by endoscope technology as standard-definition white light (SD-WLE), high-definition white light (HD-WLE) or electronic virtual chromoendoscopy (VCE) and comparisons made between these groups.Results:A total of N = 27 studies were identified, of which N = 12 were included in a meta-analysis of correlations between endoscopic and histological activity scores. Combining these studies identified considerable heterogeneity (I2: 89–93%) and returned a pooled correlation coefficient (ρ) for the SD-WLE group of 0.74, which did not differ significantly from HD-WLE (ρ: 0.65, p = 0.521) or VCE (ρ: 0.70, p = 0.801). In addition, N = 4 studies reported the accuracy of endoscopic activity scores on WLE and VCE to diagnose histological remission. Pooling these found significantly higher accuracy for VCE, compared with WLE [risk ratio: 1.13, 95% confidence interval (CI): 1.07–1.19, p < 0.001].Conclusion:Activity scores assessed using endoscopy are strongly correlated with activity on histology regardless of endoscopic technology. VCE seems to be more accurate in predicting histological remission than WLE. However, given the heterogeneity between the included studies, head-to-head trials are warranted to confirm these findings.

Assessment of Endoscopic Healing by Using Advanced Technologies Reflects Histological Healing in Ulcerative Colitis.

Several studies have reported that ulcerative colitis [UC] patients with endoscopic mucosal healing may still have histological inflammation. We investigated the relationship between mucosal healing defined by modified PICaSSO [Paddington International Virtual ChromoendoScopy ScOre], Mayo Endoscopic Score [MES] and probe-based confocal laser endomicroscopy [pCLE] with histological indices in UC. A prospective study enrolling 82 UC patients [male 66%] was conducted. High-definition colonoscopy was performed to evaluate the activity of the disease with MES assessed with High-Definition MES [HD-MES] and modified PICaSSO and targeted biopsies were taken; pCLE was then performed. Receiver operating characteristic [ROC] curves were plotted to determine the best thresholds for modified PICaSSO and pCLE scores that predicted histological healing according to the Robarts Histopathology Index [RHI] and ECAP 'Extension, Chronicity, Activity, Plus' histology score. A modified PICaSSO of ≤ 4 predicted histological healing at RHI ≤ 3, with sensitivity, specificity, accuracy and area under the ROC curve [AUROC] of 89.8%, 95.7%, 91.5% and 95.9% respectively. The sensitivity, specificity, accuracy and AUROC of HD-MES to predict histological healing by RHI were 81.4%, 95.7%, 85.4% and 92.1%, respectively. A pCLE ≤ 10 predicted histological healing with sensitivity of 94.9%, specificity of 91.3%, accuracy of 93.9% and AUROC of 96.5%. An ECAP of ≤ 10 was predicted by modified PICaSSO ≤ 4 with accuracy of 91.5% and AUROC of 95.9%. Histological healing by RHI and ECAP is accurately predicted by HD-MES and modified virtual electronic chromoendoscopy PICaSSO, endoscopic score; and the use of pCLE did not improve the accuracy any further.

P299 A prospective randomised trial comparing dye-based chromoendoscopy with electronic virtual chromoendoscopy for detection of colonic neoplastic lesions during IBD surveillance colonoscopy

Abstract Background Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal cancer. Dye-based chromoendoscopy (CE) is the currently recommended method for the detection of dysplasia in IBD surveillance colonoscopy; the role of virtual chromoendoscopy (VCE) is not yet well defined. To compare CE with VCE using iSCAN1 digital image enhanced colonoscopy in the detection of colonic neoplastic lesions in IBD patients. Methods Randomised, single-centre trial to assess the detection rate of colonic neoplastic lesions in patients with long-standing IBD. Patients were randomised in two arms: dye-spraying CE using indigo carmine and electronic VCE using iSCAN1 digital image. Detection rates of dysplasia or any neoplastic lesion were compared by the two endoscopic techniques. Results A total of 129 patients were studied (67 by CE and 62 by VCE). Demographic and clinical characteristics were homogeneous in the two groups; 26 Crohn′s disease and 103 ulcerative colitis, 52% women, mean age 50 years, median duration of IBD 204 months, family history of colorectal cancer in 10 (8%), associated primary sclerosing cholangitis in 8 (6%), personal history of colorectal dysplastic lesions in 12 (9%), and more than 50% colonic involvement in 72 (56%). In total, 27 lesions (9 hyperplastic, 8 adenomatous and 10 low-grade dysplasia) were detected in 23 patients, without differences between CE and VCE arms (15 [22%] and 12 [19%] lesions, respectively; p = 0.98); on the other hand, neoplastic lesion (dysplasia or adenoma) detection rates was similar (12 [18%] in CE and 6 [10%] in VCE arms, p = 0.2). The duration of the withdrawal time of colonoscopy in minutes for patients in the CE group was median 14 min and in the VCE group was median 10 min (p &amp;lt; 0.001). Conclusion There is no statistical difference between CE and VCE using iSCAN1 in the detection rate of colonic neoplastic lesions in IBD patients. Surveillance colonoscopy with VCE (iSCAN1) spends less time than conventional CE.

P254 Re-defining the concept of endoscopic and histological healing by using electronic virtual chromoendoscopy and probe confocal endomicroscopy in ulcerative colitis

P254 Re-defining the concept of endoscopic and histological healing by using electronic virtual chromoendoscopy and probe confocal endomicroscopy in ulcerative colitis

P164 Mucosal healing (MH) assessed with PICaSSO (Paddington International Virtual ChromoendoScopy ScOre) and probe Confocal Laser Endomicroscopy (pCLE) do not reflect histological normalisation using the ECAP (Extent Chronicity Activity Plus) score

Ulcerative colitis (UC) is a chronic disease that requires long-term therapy and the achievement of mucosal healing (MH) is the target of the treatment. The new histological score ECAP (Extent Chronicity Activity Plus) has been developed to detect minimal chronic changes. The electronic Virtual Chromoendoscopy Endoscopy (VCE) score PICaSSO (Paddington International Virtual ChromoendoScopy ScOre)1 and probe Confocal Laser Endomicroscopy (pCLE) scores reflect acute histological changes (Robarts Histological Index-[RHI]) well,2 but it is unknown whether these may reflect chronic histological changes. This is a prospective study involving 82 UC patients at the Endoscopy Unit, Foothills Medical Center, University of Calgary, Canada. For each patient, clinical data including follow-up up to 12 months, endoscopic scores (Mayo endoscopic score, PiCasso and pCLE score) and histological ECAP score were determined. The details of ECAP score has already been published.1 Receiver-operating characteristics (ROC) curves were plotted to estimate the cut-offs for PICaSSO and pCLE scores best predicting the MH determined by histological ECAP score. 70 patients (85.4%) were in clinical remission. We have compared the endoscopic scores (MES, PICaSSO, and pCLE) with histological healing defined by ECAP ≤ 4. Only 14 patients (28.6%) with Mayo 0 had ECAP ≤ 4. From the ROC curves, the best cut-off for PICaSSO score was 4, with sensitivity and specificity of 88.9% (95% CI 64.3%-98.6%) and 40.6% (95% CI 28.5%-53.6%), respectively with an area under ROC curve (AUROC) of 69.9% (95% CI 57.2%-82.6%). At this value, out of 54 patients with PICaSSO ≤ 4, only 16 (29.6%) have ECAP ≤ 4. The ROC curves for pCLE showed that the best cut-off point to detect MH (ECAP ≤ 4) was 11 with sensitivity of 94.4% (95% CI 72.7–99.9%) specificity of 31.3% (95% CI 20.2%-44.1%) with AUROC of 71.4% (95% CI 57.9%-84.8%). At this value of pCLE, 17 (27.9%) patient amongst 61 had ECAP ≤ 4. ROC curve for PICaSSO in the prediction of mucosal healing (ECAP ≤ 4) During the follow-up period, 8.06% of patients had a relapse: 80% had PICaSSO score ≤ 4, 80% had pCLE ≤ 11, and only one relapse 20% had ECAP ≤ 4. According our results, the endoscopic scores (PICaSSO and pCLE) are not able to predict histological healing calculated using ECAP (both chronic and acute changes) at the value ≤ 4. An ECAP score ≤4 may however predict stable mucosal healing with few relapses over 12 months.

The Paddington International Virtual Chromoendoscopy Score in ulcerative colitis exhibits very good inter-rater agreement after computerized module training: a multicenter study across academic and community practice (with video)

Electronic virtual chromoendoscopy (EVC) can demonstrate ongoing disease activity in ulcerative colitis (UC), even when Mayo subscores suggest healing. However, applicability of EVC technology outside the expert setting has yet to be determined. Fifteen participants across 5 centers reviewed a computerized training module outlining high-definition and EVC (iScan) colonoscopy modes. Interobserver agreement was then tested (Mayo score, Ulcerative Colitis Endoscopic Index of Severity [UCEIS], and the Paddington International Virtual Chromoendoscopy Score [PICaSSO] for UC), using a colonoscopy video library (30 cases reviewed pretraining and 30 post-training). Knowledge sustainability was retested in a second round (42 cases; 9/15 participants), 6 months after training provision. Pretraining intraclass correlation coefficients (ICC) were good for the Mayo endoscopic subscore (ICC, .775), UCEIS scoring erosions/ulcers (ICC, .770), and UCEIS overall (ICC, .786) and for mucosal (ICC, .754) and vascular components of PICaSSO (ICC, .622). For the vascular components of UCEIS, agreement was only moderate (ICC, .429) and did not enhance post-training (ICC, .417); conversely, use of PICaSSO improved post-training (mucosal ICC, .848; vascular, .746). Histologic correlation using the New York Mt. Sinai System was strong for both PICaSSO components (Spearman's ρ for mucosal: .925; vascular, .873; P< .001 for both). Moreover, accuracy in specifically discriminating quiescent from mild histologic strata was strongest for PICaSSO (area under the receiver operating characteristic curve [AUROC] for mucosal, .781; vascular, .715) compared with Mayo (AUROC, .708) and UCEIS (AUROC for UCEIS overall, .705; vascular, .562; bleeding, .645; erosions/ulcers, .696). Inter-rater reliability for PICaSSO was sustained by round 2 participants (round 1 and 2 ICC for mucosal, .873 and .869, respectively; vascular, .715 and .783, respectively), together with histologic correlation (ρ mucosal, .934; vascular, .938; P< .001 for both). PICaSSO demonstrates good interobserver agreement across all levels of experience, providing excellent correlation with histology. Given the ability to discriminate subtle endoscopic features, PICaSSO may be applied to refine stratified treatment paradigms for UC patients.

A Randomized Trial Comparing High Definition Colonoscopy Alone With High Definition Dye Spraying and Electronic Virtual Chromoendoscopy for Detection of Colonic Neoplastic Lesions During IBD Surveillance Colonoscopy.

Dye spraying chromoendoscopy (DCE) is recommended for the detection of colonic neoplastic lesions in inflammatory bowel disease (IBD). The majority of neoplastic lesions are visible endoscopically and therefore targeted biopsies are appropriate for surveillance colonoscopy. To compare three different techniques for surveillance colonoscopy to detect colonic neoplastic lesions in IBD patients: high definition (HD), (DCE), or virtual chromoendoscopy (VCE) using iSCAN image enhanced colonoscopy. A randomized non-inferiority trial was conducted to determine the detection rates of neoplastic lesions in IBD patients with longstanding colitis. Patients with inactive disease were enrolled into three arms of the study. Endoscopic neoplastic lesions were classified by the Paris classification and Kudo pit pattern, then histologically classified by the Vienna classification. A total of 270 patients (55% men; age range 20-77 years, median age 49 years) were assessed by HD (n=90), VCE (n=90), or DCE (n=90). Neoplastic lesion detection rates in the VCE arm was non-inferior to the DCE arm. HD was non-inferior to either DCE or VCE for detection of all neoplastic lesions. In the lesions detected, location at right colon and the Kudo pit pattern were predictive of neoplastic lesions (OR 6.52 (1.98-22.5 and OR 21.50 (8.65-60.10), respectively). In this randomized trial, VCE or HD-WLE is not inferior to dye spraying colonoscopy for detection of colonic neoplastic lesions during surveillance colonoscopy. In fact, in this study HD-WLE alone was sufficient for detection of dysplasia, adenocarcinoma or all neoplastic lesions.

Sa1049 The Virtual Electronic Chromoendoscopy (Vec) Score in Ulcerative Colitis Exhibits Very Good Inter-Rater Agreement in Scoring Mucosal and Vascular Changes After Computerised Module Training: A Study Across Academic and Community Practice

Sa1049 The Virtual Electronic Chromoendoscopy (Vec) Score in Ulcerative Colitis Exhibits Very Good Inter-Rater Agreement in Scoring Mucosal and Vascular Changes After Computerised Module Training: A Study Across Academic and Community Practice

Development and reliability of the new endoscopic virtual chromoendoscopy score: the PICaSSO (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis

Endoscopic inflammation and healing are important therapeutic endpoints in ulcerative colitis (UC). We developed and validated a new electronic virtual chromoendoscopy (EVC) score that could reflect the full spectrum of mucosal and vascular changes including mucosal healing in UC. Eight participants reviewed a 60-minute training module outlining 3 different i-SCAN modes demonstrating the entire spectrum of inflammatory mucosal and vascular changes in UC. Performance characteristics in endoscopic scoring and predicting the histologic inflammation with EVC (i-SCAN) by using 20 video clips before (pre-test) and after (post-test) were evaluated. Exploratory univariate factor analysis was performed on Paddington International Virtual Chromoendoscopy Score (PICaSSO) covariates for mucosal and vascular score separately. Subsequently, a proportional odds logistic regression model for the prediction of histologic scores was analyzed. The interobserver agreement for Mayo endoscopic score in the pre-test (κ= .85; 95% CI, .78-.90) and the post-test (κ= .85; 95% CI, .77-.90) evaluation were very good. This was also true for the Ulcerative Colitis Endoscopic Index of Severity in the pre-test and post-test score interobserver agreement (κ= .86; 95% CI, .77-.92; and κ= .84; 95% CI, .75-.91, respectively). The interobserver agreement of the PICaSSO endoscopic score was very good in the pre-test and post-test evaluations (κ= .92; 95% CI, .87-.96; and κ= .89; 95% CI, .84-.94, respectively). The accuracy of the overall PICaSSO in assessing histologic abnormalities and inflammation by Harpaz score was 57% (95% CI, 48%-65%), by Robarts Histological Index 72% (95% CI, 64%-79%), and by the extent, chronicity, activity, plus system (full spectrum of histologic changes) 83% (95% CI, 76%-88%). The EVC score "PICaSSO" showed very good interobserver agreement. The new EVC score may be used to define the endoscopic findings of mucosal and vascular healing in UC and reflected the full spectrum of histologic changes.

Beyond white light: optical enhancement in conjunction with magnification colonoscopy for the assessment of mucosal healing in ulcerative colitis.

Background and study aim The I-SCAN optical enhancement (OE) system with magnification is a recently introduced combination of optical and digital electronic virtual chromoendoscopy, which enhances mucosal and vascular details. The aim of this pilot study was to investigate the use of I-SCAN OE in the assessment of inflammatory changes in ulcerative colitis (UC). Patients and methods A total of 41 consecutive patients with UC and 9 control patients were examined by I-SCAN OE (Pentax Medical, Tokyo, Japan). Targeted biopsies of the imaged areas were obtained. A new optical enhancement score focusing on mucosal and vascular changes was developed. The diagnostic accuracy of I-SCAN OE was calculated against histology using two UC histological scores - Robarts Histopathology Index (RHI) and ECAP (Extent, Chronicity, Activity, Plus additional findings). Results The overall I-SCAN OE score correlated with ECAP (r = 0.70; P < 0.001). The accuracy of the overall I-SCAN OE score to detect abnormalities by ECAP was 80 % (sensitivity 78 %, specificity 100 %). I-SCAN OE vascular and mucosal scores correlated with ECAP (r = 0.65 and 0.71, respectively; P < 0.001). The correlation between overall I-SCAN OE score and RHI was r = 0.61 (P < 0.01), and the accuracy to detect abnormalities by RHI was 68 % (sensitivity 78 %, specificity 50 %). The majority of patients with Mayo 0 had abnormalities on I-SCAN OE. Conclusion In UC, the new I-SCAN OE technology accurately identified mucosal inflammation, and correlated well with histological scores of chronic and acute changes.

DOP068 The virtual electronic chromoendoscopy score in ulcerative colitis exhibits very good inter-rater agreement in scoring mucosal and vascular changes after computerised module training: a study across academic and community practice

Background: Mucosal healing is the desired therapeutic endpoint for clinical trials in ulcerative colitis (UC). However, conventional white light endoscopy may fall short of capturing the full spectrum of inflammatory change; and virtual electronic chromoendoscopy (VEC) can show ongoing disease activity even when Mayo scores suggest healing (Iacucci et al. Endoscopy 2015). Applicability of VEC scoring requires determination outside the expert setting; thus, our aim was to provide external validation among trainees, consultant gastroenterologists and colorectal surgeons, practicing across six general and specialist centres. Methods: 15 participants reviewed a computerised training module outlining HD and i-Scan modes. Anchor points for the VEC score indicated mucosal changes (crypt distortion, 0 [A–C]; microerosions, I [1–3]; erosions, II [1–3]; and ulceration, III [1–3]) and vascular alterations (non-dilated vessels, 0 [A–C]; dilated/crowded vessels, I [1–3]; mucosal bleeding, II [1–3]; and intraluminal bleeding, III [1–3]). Performance accuracy was tested using a video library pre-/post-training (n=30). Agreement between raters was tested for the Mayo score, UCEIS and VEC score, and results correlated with histology (New York Mount Sinai system; Harpaz et al.). Results: The inter-rater agreement was very good for the Mayo score, UCEIS scoring erosions/ulcers and overall, and for VEC scoring mucosal patterns in both modules (Table 1). For the vascular components of UCEIS agreement was only moderate, and did not improve post-training; unlike the agreement for VEC vascular patterns which improved significantly to very good. Correlation between histology and VEC score was highly significant for mucosal and vascular scoring (Spearman's ρ: 0.910, p<0.001; and 0.907, p<0.001; respectively, Figure 1). This was superior to the Mayo score (0.876, p<0.001) and UCEIS (0.887, p<0.001). Table 1. ICCs are from a two-way random model with absolute agreement, and are for single measures. All values are significant at a p<0.001. Figure 1. Correlation between the EVC score and histology in ulcerative colitis. Average score per video per participant for each category are presented (post-training). Conclusions: The VEC score demonstrates very good inter-observer agreement across all levels of experience and provides excellent correlation with histology. Unlike UCEIS, the VEC score does not have subjective elements (e.g. mucosal erythema, incidental/contact friability) and may better delineate vascular changes due to filter technology. Given the ability to define subtle endoscopic features, VEC may be applied to further stratify treatment paradigms for patients with UC.

624 Final Results of a Randomized Study Comparing High Definition Colonoscopy Alone With High Definition Dye Spraying and Electronic Virtual Chromoendoscopy Using iSCAN for Detection of Colonic Neoplastic Lesions During IBD Surveillance Colonoscopy

624 Final Results of a Randomized Study Comparing High Definition Colonoscopy Alone With High Definition Dye Spraying and Electronic Virtual Chromoendoscopy Using iSCAN for Detection of Colonic Neoplastic Lesions During IBD Surveillance Colonoscopy

P278. Real-time histology at endoscopy: virtual electronic chromoendoscopy and probe confocal laser endomicroscopy can assess fine details of inflammatory changes in ulcerative colitis patients

P278. Real-time histology at endoscopy: virtual electronic chromoendoscopy and probe confocal laser endomicroscopy can assess fine details of inflammatory changes in ulcerative colitis patients

DOP080. Final results of a randomised study comparing high-definition colonoscopy alone with high- definition dye spraying and electronic virtual chromoendoscopy using iSCAN for detection of colonic neoplastic lesions during IBD surveillance colonoscopy

DOP080. Final results of a randomised study comparing high-definition colonoscopy alone with high- definition dye spraying and electronic virtual chromoendoscopy using iSCAN for detection of colonic neoplastic lesions during IBD surveillance colonoscopy

327 A Randomized Comparison of High Definition Colonoscopy Alone With High Definition Dye Spraying and Electronic Virtual Chromoendoscopy Using iSCAN for Detection of Colonic Dysplastic Lesions During IBD Surveillance Colonoscopy

327 A Randomized Comparison of High Definition Colonoscopy Alone With High Definition Dye Spraying and Electronic Virtual Chromoendoscopy Using iSCAN for Detection of Colonic Dysplastic Lesions During IBD Surveillance Colonoscopy

P146. Detection and characterization of colonic dysplastic lesions in IBD surveillance colonoscopy - a randomised comparison of high definition alone with high definition dye spraying and electronic virtual chromoendoscopy using iSCAN

P146. Detection and characterization of colonic dysplastic lesions in IBD surveillance colonoscopy - a randomised comparison of high definition alone with high definition dye spraying and electronic virtual chromoendoscopy using iSCAN