Real-time computer-aided diagnosis of diminutive rectosigmoid polyps using an auto-fluorescence imaging system and novel color intensity analysis software

Abstract

Objectives: An endoscopic technique that provides ≥90% negative predictive value (NPV) for differentiating neoplastic polyps is needed for the management of diminutive (≤5?mm) rectosigmoid polyps. This study aimed to assess whether a newly developed software can achieve ≥90% NPV for differentiating rectosigmoid diminutive polyps based on the green-to-red (G/R) ratio, obtained by dividing the green color tone intensity by the red color tone intensity on autofluorescence imaging (AFI).

Methods: From December 2017 to May 2018, consecutive patients with known polyps who were scheduled for endoscopic treatment at our institution were prospectively recruited. All colorectal diminutive polyps were differentiated by computer-aided diagnosis using autofluorescence imaging (CAD-AFI) using a novel software-based automatic color intensity analysis; subsequent diagnosis was made by endoscopists based on trimodal imaging endoscopy (TME), which combines AFI, white-light imaging (WLI) and magnifying narrow-band imaging (M-NBI) findings. Thereafter, all polyps were removed endoscopically, and the histopathological diagnosis was evaluated.

Results: Ninety-five patients with 258 diminutive rectosigmoid polyps and 171 diminutive non-rectosigmoid polyps were enrolled. Regarding diminutive rectosigmoid polyps, the NPV for differentiating neoplastic polyps was 93.4% (184/197) [95% confidence interval (CI), 89.0%–96.4%] with CAD-AFI and 94.9% (185/195) (95% CI, 90.8%–97.5%) with TME. The accuracy, sensitivity, specificity, and positive predictive value for differentiating diminutive rectosigmoid neoplastic polyps by CAD-AFI were 91.5%, 80.0%, 95.3% and 85.2%, respectively.

Conclusions: Real-time CAD-AFI was effective for differentiating diminutive rectosigmoid polyps. This objective technology, which does not require extensive training or endoscopic expertise, can contribute to the effective management of diminutive rectosigmoid polyps.     

普通窄带成像内镜对结直肠增生性息肉和腺瘤的鉴别诊断价值

目的 分析普通窄带成像(NBI)内镜下结直肠增生性息肉与腺瘤腺管及微血管特征的差异,评价NBI的鉴别诊断价值.方法 将普通内镜下诊断结直肠息肉、病理检查证实为增生性息肉或腺瘤者纳入研究并进行NBI内镜检查.将腺管形态参照改良的工藤分型法分为A型和B型.将微血管形态分为3型,无微血管判为Ⅰ型,微血管沿腺管开口排列、粗细均匀判为Ⅱ型,微血管粗细不均、排列紊乱判为Ⅲ型.比较增生性息肉和腺瘤NBI图像中腺管形态和微血管形态特征的差异,同时对无放大NBI图像观察者间的一致性进行评价.结果 共87例患者的107个息肉(腺瘤73个、增生性息肉34个)进行普通NBI内镜检查.腺瘤组息肉最大径和表面分叶者比例明显高于增生性息肉组(P值分别=0.0023和0.0047).腺瘤组中B型腺管形态[86.3％(63/73)]及Ⅱ或Ⅲ型微血管形态[82.2％(60/73)]者较多.以B型腺管形态、Ⅱ型或Ⅲ型微血管中任一特征诊断腺瘤的敏感度、特异度、准确率分别为97.3％、82.4％、92.5％.以B型腺管形态联合Ⅱ型或Ⅲ型微血管诊断腺瘤的敏感度、特异度、准确率分别为71.2％、91.2％、77.6％.观察者间一致性评价平均Kappa值为0.761.结论 普通NBI内镜下结直肠腺瘤和增生性息肉的微血管特征和腺管特征存在差异,依据以上两方面可在NBI内镜下实时初步鉴别腺瘤和增生性息肉.     

White light endoscopy, narrow band imaging and chromoendoscopy with magnification in diagnosing colorectal neoplasia

AIM: To evaluate the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 3 different techniques: high resolution white light endoscopy (WLE), Narrow Band Imaging (NBI) and Chromoendoscopy (CHR), all with magnification in differentiating adenocarcinomas, adenomatous and hyperplastic colorectal polyps.METHODS: Each polyp was sequentially assessed first by WLE, followed by NBI and finally by CHR. Digital images of each polyp with each modality were taken and stored. Biopsies or polypectomies were then performed followed by blinded histopathological analysis. Each image was blindly graded based on the Kudo’s pit pattern (KPP). In the assessment with NBI, the mesh brown capillary network pattern (MBCN) of each polyp was also described. The Sn, Sp, PPV and NPV of differentiating hyperplastic (Type I & II-KPP, Type I-MBCN) adenomatous (Types III, IV-KPP, Type II-MBCN) and carcinomatous polyps (Type V-KPP, Type III-MCBN) was then compared with reference to the final histopathological diagnosis.RESULTS: A total of 50 colorectal polyps (5 adenocarcinomas, 38 adenomas, 7 hyperplastic) were assessed. CHR and NBI [KPP, MBCN or the combined classification (KPP & MBCN)] were superior to WLE in the prediction of polyp histology (P < 0.001, P = 0.002, P = 0.001 and P < 0.001, respectively). NBI, using the MBCN pattern or the combined classification showed higher numerical accuracies compared to CHR, but this was not statistically significant (P = 0.625, 0.250).CONCLUSION: This feasibility study demonstrated that this combined classification with NBI could potentially be useful in routine clinical practice, allowing the endoscopist to predict histology with higher accuracies using a less cumbersome and technically less challenging method.     

Meta-analysis for evaluating the accuracy of endoscopy with narrow band imaging in detecting colorectal adenomas

Background and Aim: The aim of this study was to determine whether the use of the narrow band imaging (NBI) system could enhance the accuracy of adenoma detection during an endoscopic examination of the colon and rectum. Methods: MEDLINE, EMBASE, and the Cochrane Library databases were searched along with a hand search of abstracts from relevant conferences up to June 2011. The rates of adenoma and flat adenoma detection, and withdrawal time were analyzed using Review Manager 4.2. Results: A total of 3049 subjects in eight trials were included. Meta‐analysis revealed that there was no statistically significant difference in the rates of adenoma detection between the NBI group and the white light colonoscopy group (pooled relative risk [RR]: 1.09, 95% confidence interval [CI]: 1.00–1.19, P = 0.05). However, after exclusion of high‐definition television modalities, the rate of adenoma detection by NBI was significantly higher than that by white light, particularly for patients with one adenoma (pooled RR 1.36, 95%CI 1.07–1.71, P = 0.02). Endoscopy with the NBI system significantly increased the rate of flat adenoma detection (pooled RR 1.96, 95%CI 1.09–3.52, P = 0.02). However, endoscopy with NBI had longer withdrawal time than that with white light (pooled weighted mean difference: 0.90, 95%CI: 0.38–1.42, P = 0.0006). Conclusions: Endoscopy with NBI seems to improve the detection of flat adenomas, particularly with high‐definition technology, but prolongs the withdrawal time. These results indicate that endoscopy routinely using the NBI system for the surveillance of adenomas may be recommended after the technique is further modified.     

Magnifying narrow-band imaging with acetic acid to diagnose early colorectal cancer

AIM:To evaluate the diagnostic characteristics of magnifying endoscopy with acetic acid spray and narrowband imaging(MA-NBI)for early colorectal cancer.METHODS:We conducted a prospective study to evaluate the diagnostic characteristics of MA-NBI in differentiating early colorectal adenocarcinomas from adenomas.To compare the results,we used magnifying endoscopy with NBI(M-NBI)and magnifying endoscopy with crystal violet staining(M-CV).The study was performed in 2 phases.In phase 1,10 colonoscopists at our institution were shown still photographs of 35colorectal polyps(24 adenocarcinomas and 11 adenomas)in M-NBI,MA-NBI,and M-CV.They made diagnostic predictions using a five-grade scoring evaluation.We plotted receiver operating characteristic curves and compared the areas under the curves(AUCs).In phase2,colorectal polyps measuring≥8 mm were prospectively enrolled.During real-time colonoscopy,one ofthe 7 colonoscopists scored the lesion as an adenocarcinoma or an adenoma and assigned a level of confidence to the prediction(high or low).We calculated the accuracy,sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)for each method and compared the proportions of highconfidence predictions.RESULTS:In phase 1,the mean±SD AUCs were 0.64±0.031 in M-NBI,0.71±0.066 in MA-NBI,and 0.76±0.059 in M-CV(P<0.05 for M-NBI vs MA-NBI,P<0.001 for M-NBI vs M-CV,and not significant for MANBI vs M-CV).In phase 2,84 patients with 91 lesions(46 adenocarcinomas and 45 adenomas)were enrolled.The diagnostic characteristics were as follows:73%accuracy,85%sensitivity,60%specificity,68%PPV,and 79%NPV in M-NBI;73%accuracy,80%sensitivity,64%specificity,70%PPV,and 76%NPV in MA-NBI;and 73%accuracy,83%sensitivity,62%specificity,69%PPV,and 78%NPV in M-CV.The proportions of high-confidence predictions were 57%in M-NBI,75%in MA-NBI,and 76%in M-CV(P<0.005 for M-NBI vs MA-NBI,P<0.0005 for M-NBI vs M-CV,and P=1.0 for MA-NBI vs M-CV).CONCLUSION:MA-NBI is useful for differentiating early colorectal adenocarcinomas from adenomas.     

内镜窄带光成像对儿童食管息肉的诊断价值

为探讨内镜窄带光成像技术（narrow?band imaging，NBI）对儿童食管息肉的诊断价值，在白光内镜及NBI内镜下分别对2016年1月—2020年6月上海市儿童医院的35例患儿的食管息肉进行微细形态的观察，以病理检查结果作为金标准，分析和对比白光内镜与NBI内镜诊断息肉的灵敏度及特异度。35例患儿共发现食管息肉70枚，其中27例患儿为单发息肉。病理结果提示息肉以非肿瘤性息肉为多（52.9%，37/70）。NBI内镜诊断肿瘤性息肉的灵敏度［93.9%（31/33）比90.9%（30/33）］和特异度［89.2%（33/37）比78.4%（29/37）］优于传统白光内镜，灵敏度差异有统计学意义（P<0.001），特异度差异无统计学意义（P=0.864）。NBI内镜通过观察食管息肉的微细结构，有助于临床预判息肉的病理性质，其灵敏度优于白光内镜。     

Differential diagnosis of colorectal polyps with respect to similar capabilities of white light colonoscopy and narrow-band imaging

Purpose

The responses of polyps to light essentially determine the diagnostic capability of an endoscopy system in differentiating adenomas from hyperplastic polyps. Compared with white light colonoscopy (WLC), narrow-band imaging (NBI) is expected to improve the diagnostic capability. The diagnostic capabilities of WLC and NBI are evaluated and compared based on the polyp responses.

Methods

The following WLC and NBI images were retrospectively reviewed and categorized: 195 images and polyps (89 WLC, 106 NBI) with the best visual quality were categorized in the best image group (BG), and 484 images of 242 polyps (both WLC and NBI) were categorized in the paired image group (PG). For each reflection of light used for WLC or NBI, the polyp responses were objectively expressed as reflection features. The reflection features were then used to establish a classification model for identifying adenomas. The diagnostic capability of reflection feature or classification model was measured by the area under the receiver operating characteristic curve (AUC).

Results

In both image groups, the diverse and heterogeneous features of the polyp responses enabled accurate identification of adenomas, regardless of the light source used for WLC and NBI. For differential diagnosis of adenomas and hyperplastic polyps, the WLC and NBI did not significantly differ in BG (AUC, 0.905 and 0.922, respectively; P?=?0.690) or in PG (AUC, 0.782 and 0. 769, respectively; P?=?0.755).

Conclusions

Using WLC and NBI as classification models is effective in differential diagnosis of colorectal polyps and exhibited similar capabilities.     

Comparative study of conventional colonoscopy, chromoendoscopy, and narrow-band imaging systems in differential diagnosis of neoplastic and nonneoplastic colonic polyps

AIM: To identify the feasibility of the narrow-band imaging (NBI) method compared with that of conventional colonoscopy and chromoendoscopy for distinguishing neoplastic and nonneoplastic colonic polyps. METHOD: This study enrolled consecutive patients who underwent colonoscopy using a conventional colonoscope between January and February 2006 at Chang-Gung Memorial Hospital, Linkou Medical Center, Taiwan. These 78 patients had 110 colorectal polyps. During the procedure, conventional colonoscopy first detected lesions, and then the NBI system was used to examine the capillary networks. Thereafter indigo carmine (0.2%) was sprayed directly on the mucosa surface prior to evaluating the crypts using a conventional colonoscope. The pit patterns were characterized using the classification system proposed by Kudo. Finally, a polypectomy or biopsy was performed for histological diagnosis. RESULTS: Of the 110 colorectal polyps, 65 were adenomas, 40 were hyperplastic polyps, and five were adenocarcinomas. The NBI system and pit patterns for all lesions were analyzed. For differential diagnosis of neoplastic (adenoma and adenocarcinoma) and nonneoplastic (hyperplastic) polyps, the sensitivity of the conventional colonoscope for detecting neoplastic polyps was 82.9%, specificity was 80.0% and diagnostic accuracy was 81.8%, significantly lower than those achieved with the NBI system (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%) and chromoendoscopy (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%). Therefore, no significant difference existed between the NBI system and chromoendoscopy during differential diagnosis of neoplastic and nonneoplastic polyps. CONCLUSION: The NBI system identified morphological details that correlate well with polyp histology by chromoendoscopy.     

Narrow-band imaging colonoscopy--a pilot feasibility study for the detection of polyps and correlation of surface patterns with polyp histologic diagnosis

BACKGROUND: Colonoscopy is the preferred screening method for colorectal cancer. However, it has a substantial miss rate for colon polyps, and several techniques have been attempted to improve this limitation. Narrow-band imaging (NBI) is a novel technology that enhances the visualization of surface mucosal and vascular patterns. OBJECTIVE: The aim of this study was to determine the detection rate of additional polyps by NBI after removal of polyps visualized by standard white light colonoscopy (WLC) and to correlate the surface mucosal and vascular patterns with polyp histologic diagnosis. DESIGN: This was a prospective pilot feasibility study. SETTING: Kansas City Veterans Affairs Medical Center. PATIENTS: Subjects referred for screening colonoscopy were prospectively enrolled. METHODS: Subjects underwent colonoscopy after enrollment. After intubation of the cecum, colonic segments were sequentially examined, initially with WLC with removal of polyps followed by re-examination of the same segment with NBI. Additional polyps seen with NBI were photographed for their surface patterns and then removed. The total number of polyps visualized by WLC and NBI was calculated and the surface patterns were then correlated with polyp histologic features. RESULTS: Forty patients were enrolled in the study, all men, 32 white. The mean age was 62 years. A total of 72 polyps were detected by WLC (43 tubular adenoma, 28 hyperplastic polyps), whereas NBI detected an additional 51 polyps, of which 29 were tubular adenomas and 22 were hyperplastic. Five different surface/vascular patterns were observed: fine capillary network with absent mucosal pattern, circular pattern with dots, round/oval pattern, tubular pattern, and gyrus pattern. The sensitivity, specificity, and overall accuracy of the first two patterns for hyperplastic polyps were 86%, 96%, and 92%, respectively, and of the latter three patterns for tubular adenomas were 96%, 86%, and 92%, respectively. CONCLUSIONS: This pilot study demonstrates the feasibility of polyp detection and histologic correlation with NBI. These findings need to be confirmed in future randomized controlled trials.     

Gastric polyps: Association with Helicobacter pylori status and the pathology of the surrounding mucosa,a cross sectional study

aim:To assess the endoscopic characteristics of gastric polyps and their association with Helicobacter pylori(H.pylori)status in a predominantly Hispanic population.m ETHODS:We conducted a retrospective study of all esophagogastroduodenoscopies performed at our institution.Demographic,endoscopic and histopathological data were reviewed.Categorization of patients into Hispanic and Non-Hispanic was based on selfidentification.Patients without resection/biopsy were not included in the analysis.Identification of polyps type was based on histological examination.One way analysis of variance was used to compare continuousvariables among different polyp types and Fisher’s exact test was used compare categorical variables among polyp types.Unadjusted and adjusted comparisons of demographic and clinical characteristics were performed according to the H.pylori status and polyp type using logistic regressions.RESULTS:Of 7090 patients who had upper endoscopy,335 patients had gastric polyps(4.7%).Resection or biopsy of gastric polyps was performed in 296 patients(88.4%)with a total of 442 polyps removed or biopsied.Of 296 patients,87(29%)had hyperplastic polyps,82(28%)had fundic gland polyps and 5(1.7%)had adenomatous polyps.Hyperplastic polyps were significantly associated with positive H.pylori status compared with fundic gland polyps(OR=4.621;95%CI:1.92-11.13,P=0.001).Hyperplastic polyps were also found to be significantly associated with portal hypertensive gastropathy compared with fundic gland polyps(OR=6.903;95%CI:1.41-33.93,P=0.0174).Out of 296 patients,30(10.1%)had a followup endoscopy with a mean duration of 26±16.3 mo.Interval development of cancer was not noted in any of the patients during follow up period.CONCLUSi ON:Gastric hyperplastic polyps were significantly associated with positive H.pylori status and portal hypertensive gastropathy as compared with fundic gland polyps.     

Narrow-band imaging in the colon: limitations and potentials

Narrow-band imaging (NBI) is a new endoscopic technology that highlights surface structures and superficial mucosal capillaries during colonoscopy at a single push of a button. NBI has a high sensitivity and specificity for differentiating neoplastic and non-neoplastic polyps by means of mucosal and capillary patterns. It is also useful in determining the invasion depth of early colorectal cancers and evaluating free margins after endoscopic resection. However, it has not been shown to improve the adenoma detection rate compared with white-light endoscopy. Although narrow-band imaging is now available commercially, its role in routine clinical practice during colonoscopy is not well defined. The difficulties in interpreting results partly relate to different NBI nomenclatures used in classifying colonic adenomas and their lack of standardization. Future research should focus on establishing a reliable NBI nomenclature for capillary patterns, defining the learning curve and interobserver variation, and validating the effectiveness of NBI in routine colonoscopy.     

Can optical diagnosis of small colon polyps be accurate? Comparing standard scope without narrow banding to high definition scope with narrow banding

AIM: To study the accuracy of using high definition(HD) scope with narrow band imaging(NBI) vs standard white light colonoscope without NBI(ST), to predict the histology of the colon polyps, particularly those 1 cm.METHODS: A total of 147 African Americans patients who were referred to Howard University Hospital for screening or, diagnostic or follow up colonoscopy, during a 12-mo period in 2012 were prospectively recruited. Some patients had multiple polyps and total number of polyps was 179. Their colonoscopies were performed by 3 experienced endoscopists who determined the size and stated whether the polyps being removed were hyperplastic or adenomatous polyps using standard colonoscopes or high definition colonoscopes with NBI. The histopathologic diagnosis was reported by pathologists as part of routine care. RESULTS: Of participants in the study, 55(37%) were male and median(interquartile range) of age was 56(19-80). Demographic, clinical characteristics, past medical history of patients, and the data obtained by two instruments were not significantly different and two methods detected similar number of polyps. In ST scope 89% of polyps were 1 cm vs 87% in HD scope(P = 0.7). The ST scope had a positive predictive value(PPV) and positive likelihood ratio(PLR) of 86% and 4.0 for adenoma compared to 74% and 2.6 for HD scope. There was a trend of higher sensitivity for HD scope(68%) compare to ST scope(53%) with almost the same specificity. The ST scope had a PPV and PLR of 38% and 1.8 for hyperplastic polyp(HPP) compared to 42% and 2.2 for HD scope. The sensitivity and specificity of two instruments for HPP diagnosis were similar.CONCLUSION: Our results indicated that HD scope was more sensitive in diagnosis of adenoma than ST scope. Clinical diagnosis of HPP with either scope is less accurate compared to adenoma. Colonoscopy diagnosis is not yet fully matched with pathologic diagnosis of colon polyp. However with the advancement of both imaging and training, it may be possible to increase the sensitivity and specificity of the scopes and hence save money for eliminating time and the cost of Immunohistochemistry/pathology.     

Significance of serrated polyps of the colon

The fundamental view that colon adenocarcinomas arise only from conventional adenomas has been challenged by the now recognized hyperplastic polyp-serrated adenoma-adenocarcinoma pathway. This article describes the history of the serrated adenoma (both the traditional serrated adenoma and the sessile serrated adenoma) as well as the histology and endoscopic appearance of these lesions in comparison with hyperplastic polyps and mixed polyps. Although the exact pathway is the subject of ongoing research, compelling histologic associations and molecular phenotypes that define the model of the serrated polyp-carcinoma sequence, including microsatellite instability, BRAF/KRAS mutations, and CpG island methylator phenotype, provide strong evidence that this is a genuine pathway. Management of serrated neoplasia of the colon includes careful colonoscopy, complete removal of colonic polyps, sampling fields of diminutive polyps of the rectosigmoid, and basing surveillance on histology of removed polyps.     

Diminutive polyps of large bowel should be an early target for endoscopic treatment

BACKGROUND AND AIMS: Aim of the present study is to ascertain the importance of diminutive colorectal polyps and define the need for removal according to their characteristics and malignant potential. PATIENTS AND METHODS: A total of 4,723 patients who underwent colonoscopy were evaluated and 624 patients with 826 polyps were recorded. There were 352 patients with 443 diminutive polyps, studied according to their distribution. Of these, 371 were removed, histologically examined and correlated to patient characteristics and occurrence of synchronous neoplasms. RESULTS: Of the right colon polyps, 81/115 were diminutive, versus 362/711 of the left colon (p<0.0001). Adenomas were more common in patients over 50 years of age, (p<0.0001). In all colonic segments, diminutive adenomas prevailed over hyperplastic polyps, whereas the proportion of diminutive adenomas predominated in the right colon (p=0.0015). Adenomas were classified as tubular 39%, tubulovillous 55.7% and villous 5.3%. The degree of dysplasia was mild in 45.5%, moderate in 51% and severe in 3.5%. The prevalence of synchronous neoplasms was 37.4%. They were more frequently found in males over 50 years of age and in patients with diminutive adenomas compared to those with diminutive hyperplastic polyps (p=0.0078). CONCLUSIONS: The majority of right colon polyps are diminutive. The proportion of diminutive adenomas is higher in patients over 50 years and in the right vs left colon. Diminutive polyps should be removed taking into account the high prevalence of adenomas with a villous component and their significant degree of dysplasia.     

Multiple Large Hyperplastic Polyps of the Colon Coincident with Adenocarcinoma

Diminutive hyperplastic polyps are the most common non-neoplastic lesions of the colon. Typically, they are small (<0.5 cm) sessile lesions, lack cellular atypia, and are found predominantly in the rectosigmoid region of the colon. Multiple large hyperplastic polyps (>1 cm) are rare. Although the relationship between diminutive hyperplastic polyps and adenomatous polyps or carcinoma is controversial, even less data are available on the significance of large hyperplastic polyps. We report the case of a 56-yr-old man who was seen because of fatigue, anemia, and Hemoccult-positive stool. On air contrast barium enema study and colonoscopy, multiple polyps that were similar in appearance were found distributed symmetrically throughout the colon. However, histologic examination revealed 16 hyperplastic polyps 1–2 cm in size, multiple diminutive hyperplastic polyps, one adenomatous polyp, and one adenomatous polyp containing well-differentiated adenocarcinoma. Because multiple large hyperplastic polyps are rare, we suspect this entity may be distinct from diminutive hyperplastic polyps. In our patient, large hyperplastic polyps were distributed symmetrically throughout the colon and were associated with a synchronous carcinoma. Because large hyperplastic polyps may be coincident with adenomatous polyps and carcinoma of the colon, we recommend that patients found to have large hyperplastic polyps undergo removal of all polyps for histologic study.     

Randomized,back-to-back trial of a new generation NBI with a high-definition white light (HQ290) for detecting colorectal polyps

Abstract

Background: The benefits of narrow band imaging (NBI) for improving the detection rate of colorectal polyps remain unclear. New generation NBI using the 290 system (290-NBI) provides an at least two-fold brighter image than that of the previous version. We aimed to compare polyp miss rates between 290-NBI colonoscopy and high-definition white light endoscopy (HDWL).

Methods: In total, 117 patients were randomized to undergo either 290-NBI or HDWL from June 2015 to February 2017. In the HDWL group, we performed HDWL as an initial inspection, followed by a second inspection with NBI. In the 290-NBI group, NBI was performed as the initial inspection, followed by a second inspection with HDWL. We compared polyp and adenoma detection rates and polyp miss rates (PMR) between the two groups and analyzed the factors associated with the PMR.

Results: In total, 127 polyps were detected in the 117 patients. No differences in adenoma or polyp detection rates were observed between the two groups. The PMR for 290-NBI was 20.6% and that for HDWL was 33.9% (p?=?.068). However, the non-adenomatous PMR for 290-NBI was significantly lower than that of HDWL (11.5% vs. 52.2%, p?=?.002). Furthermore, the miss rates of polyps on the left side of the colon, flat-type polyps, and non-adenomatous polyps were significantly lower in the 290-NBI than HDWL.

Conclusions: New generation NBI may reduce PMR, especially of flat-type and non-adenomatous polyps and those on the left side of the colon. (UMIN000025505)     

Efficacy of a novel auto-fluorescence imaging system with computer-assisted color analysis for assessment of colorectal lesions

AIM:To evaluate the efficacy of computer-assisted color analysis of colorectal lesions using a novel auto-fluorescence imaging(AFI)system to distinguish neoplastic lesions from non-neoplastic lesions and to predict the depth of invasion.METHODS:From January 2013 to April 2013,consecutive patients with known polyps greater than 5 mm in size who were scheduled to undergo endoscopic treatment at The Jikei University Hospital were prospectively recruited for this study.All lesions were evaluated using a novel AFI system,and color-tone sampling was performed in a region of interest determined from narrow band imaging or from chromoendoscopy findings without magnification.The green/red(G/R)ratio for each lesion on the AFI images was calculated automatically using a computer-assisted color analysis system that permits real-time color analysis during endoscopic procedures.RESULTS:A total of 88 patients with 163 lesions were enrolled in this study.There were significant differences in the G/R ratios of hyperplastic polyps(non-neoplastic lesions),adenoma/intramucosal cancer/submucosal(SM)superficial cancer,and SM deep cancer(P<0.0001).The mean±SD G/R ratios were 0.984±0.118in hyperplastic polyps and 0.827±0.081 in neoplastic lesions.The G/R ratios of hyperplastic polyps were significantly higher than those of neoplastic lesions(P<0.001).When a G/R ratio cut-off value of>0.89 was applied to determine non-neoplastic lesions,the sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and accuracy were 83.9%,82.6%,53.1%,95.6%and 82.8%,respectively.For neoplastic lesions,the mean G/R ratio was 0.834±0.080 in adenoma/intramucosal cancer/SM superficial cancer and 0.746±0.045 in SM deep cancer.The G/R ratio of adenoma/intramucosal cancer/SM superficial cancer was significantly higher than that of SM deep cancer(P<0.01).When a G/R ratio cut-off value of<0.77 was applied to distinguish SM deep cancers,the sensitivity,specificity,PPV,NPV,and accuracy were80.0%,84.4%,29.6%,98.1%and 84     

Acceptability, effectiveness, and cost-effectiveness of internet-based exposure treatment for irritable bowel syndrome in a clinical sample: a randomized controlled trial

Background

A colonoscopy may frequently miss polyps and cancers. A number of techniques have emerged to improve visualization and to reduce the rate of adenoma miss.

Methods

We conducted a randomized controlled trial (RCT) in two clinics of the Gastrointestinal Department of the Sanitas University Foundation in Bogota, Colombia. Eligible adult patients presenting for screening or diagnostic elective colonoscopy were randomlsy allocated to undergo conventional colonoscopy or narrow-band imaging (NBI) during instrument withdrawal by three experienced endoscopists. For the systematic review, studies were identified from the Cochrane Library, PUBMED and LILACS and assessed using the Cochrane risk of bias tool.

Results

We enrolled a total of 482 patients (62.5% female), with a mean age of 58.33 years (SD 12.91); 241 into the intervention (NBI) colonoscopy and 241 into the conventional colonoscopy group. Most patients presented for diagnostic colonoscopy (75.3%). The overall rate of polyp detection was significantly higher in the conventional group compared to the NBI group (RR 0.75, 95%CI 0.60 to 0.96). However, no significant differences were found in the mean number of polyps (MD -0.1; 95%CI -0.25 to 0.05), and the mean number of adenomas (MD 0.04 95%CI -0.09 to 0.17). Meta-analysis of studies (regardless of indication) did not find any significant differences in the mean number of polyps (5 RCT, 2479 participants; WMD -0.07 95% CI -0.21 to 0.07; I2 68%), the mean number of adenomas (8 RCT, 3517 participants; WMD -0.08 95% CI -0.17; 0.01 to I2 62%) and the rate of patients with at least one adenoma (8 RCT, 3512 participants, RR 0.96 95% CI 0.88 to 1,04;I2 0%).

Conclusion

NBI does not improve detection of colorectal polyps when compared to conventional colonoscopy (Australian New Zealand Clinical Trials Registry ACTRN12610000456055).     

Predictive value of morphologic characteristics in rectosigmoid adenomatous polyps for the probability of synchronous polyps or cancer in the proximal colon.

BACKGROUND/AIMS: Sigmoidoscopy is performed more frequently than colonoscopy, especially for screening purposes and searching for colorectal neoplasm. The necessity of colonoscopy in patients with an adenoma ofor=11 mm) polyps. These groups were compared regarding the presence of proximal adenoma and advanced proximal neoplasia (>10 mm adenoma and/or villous histology and/or high grade dysplasia or cancer). Polyps found in the rectum and sigmoid colon were considered as distal polyps and polyps other than these were considered as proximal polyps. RESULTS: In this study, of 1124 consecutive patients who underwent colonoscopy between April 1997 and January 2002, 184 (16%) had 258 adenomatous polyps in the rectosigmoid area. The polyps were diminutive (or=11 mm) in 33 patients. Forty-one of the patients (39%) with diminutive polyps, 20 of the patients (43%) with small polyps and 19 of the patients (57%) with large polyps had neoplasm in the proximal bowel. In these patients, advanced proximal neoplasm was found in 8 (8%), in 6 (13%) and in 11 (33%), respectively. There was no difference regarding the presence of neoplasm in the proximal colon between these groups. The rate of advanced proximal neoplasm was found to be significantly higher in the group with large polyps in the rectosigmoid area than in the groups with small and diminutive polyps (p<0.05). In 104 patients (57%) with polyp(s) in rectum and sigmoid colon, no associated polyp or cancer was encountered in the proximal colon. CONCLUSION: Colonoscopy is indicated when adenomatous polyp, regardless of size, is found on rectosigmoidoscopy performed because of symptoms.     

A randomized crossover open trial of the adenoma miss rate for narrow band imaging (NBI) versus flexible spectral imaging color enhancement (FICE)

Purpose

Narrow band imaging (NBI) and flexible spectral imaging color enhancement (FICE) allow improved contrasted evaluation of the mucosal surface. However, no study has compared the utility of these two modalities. Therefore, the aim of this study was to compare the adenoma miss rate (AMR) between NBI and FICE.

Methods

A total of 55 patients (38 men, 17 women) were enrolled in this study. Patients were randomly assigned to the NBI–FICE group (NBI followed by FICE) or the FICE–NBI group (FICE followed by NBI). NBI and FICE total colonic observations were tandemly performed for each patient during the scope withdrawal with white light following cecal intubation. All detected polyps with the NBI or FICE observation were categorized into three groups according to the size and number of polyps missed.

Results

Twenty-nine patients were assigned to the NBI–FICE group, and 26 patients were assigned to the FICE–NBI group. There was no significant difference in the overall AMR when comparing the image-enhanced endoscopy technologies (17.9 % for NBI, 26 % for FICE, p?=?0.159). AMR was lower for NBI than for FICE for adenomas <5 mm in diameter (5.7 % for NBI, 12.6 % for FICE, p?=?0.036). AMR was not significantly different when comparing NBI and FICE for lesions 5 to 10 mm (p?=?0.967) or for lesions ≥10 mm (p?=?0.269).

Conclusions

This study demonstrated that overall AMR was not different when comparing NBI and FICE.