Scan the quick response (QR) code to the left with your mobile device to watch this article's video abstract and others. Don't have a QR code reader? Get one by searching 'QR Scanner' in your mobile device's app store. R ecently, the American Society of GastrointestinalEndoscopy established the Preservation and Incorporation of Valuable Endoscopic Innovations 1 for diminutive colorectal polyps. Preservation and Incorporation of Valuable Endoscopic Innovations suggests that, if an endoscopist diagnoses an agreement of >90% in determining postpolypectomy surveillance intervals and a negative predictive value of >90% with adenomatous histology, pathologic diagnosis might not be necessary. Although magnifying chromoendoscopy, 2 narrow-band imaging (NBI), 3 endocytoscopy (EC), 4 and confocal laser endomicroscopy 5 are highly accurate, interpretation of these modalities is difficult for novices. Furthermore, achieving a negative predictive value of >90% for adenoma is not easy using these modalities 3 and requires comprehensive experiments. 6 To achieve a breakthrough on this issue, we developed a computer-aided diagnosis (CAD) system for EC. This system automatically provides highly accurate diagnosis as expert endoscopists concurrently take EC images (Video Clip 1). 7 Our previous system, based on glandular structural and cellular atypia, required endoscopists to use dye for staining. In contrast, the endocytoscopic vascular pattern can effectively evaluate microvessel findings using EC with NBI (EC-NBI) without using any dye. We reported that EC-NBI has a highly accurate diagnostic ability, similar to other modalities. 8 Because dye staining complicates the procedure, our CAD system for EC-NBI represents a powerful tool for novices and experts who do not use dyes on a routine basis. Therefore, we developed a tentative CAD system model for EC-NBI image. Description of TechnologyWe developed custom software (EndoBRAIN, Cybernet Systems Co., Ltd., Tokyo, Japan) to analyze EC images. We collected a consecutive series of 1079 EC-NBI images (431 nonneoplasms and 648 neoplasms) from 85 lesions to form an image database. To validate the CAD system, we randomly extracted 100 images (50 nonneoplasms, 50 neoplasms) from the database. The remaining 979 images (381 nonneoplasms, 598 neoplasms) were used for machine learning. The inclusion criteria were colorectal lesions that had been detected during colonoscopy using EC and subsequently resected between December 2014 and April 2015. The exclusion criteria were inflammatory bowel disease; lesions for which no clear EC-NBI were available; sessile serrated adenomas/polyps (SSA/Ps); and nonepithelial Figure 1. Output image. (1) Computer diagnosis. (2) Input endocytoscopy with narrow band imaging. (3) Extracted vessel image, in which the green area denotes the extracted vessels. The light-green vessel has the maximum diameter. (4) Probability of computer diagnosis is calculated by the support vector machine classifier.Abbreviations used in this paper: CAD, computer-aided diagnosis; ...

EC) is a contact-type optical endoscope that allows in vivo cellular observation during gastrointestinal endoscopy and is now commercially available not only in Japan but also in Asian, European Union, and Middle Eastern countries. EC helps conduct a highly accurate pathological prediction without biopsy. Initially, EC was reported to be effective for esophageal diseases. Subsequently, its efficacy for stomach and colorectal diseases has been reported. In this narrative review, we searched for clinical studies that investigated the efficacy of EC. EC seems to accurately diagnose gastrointestinal diseases without biopsy. Most of the studies aimed to clarify the relationship between endocytoscopic findings of gastrointestinal neoplasia and pathological diagnosis. Some studies have investigated non-epithelial lesions or diseases, such as inflammatory bowel disease or infectious diseases. However, there are few high-level pieces of evidence, such as randomized trials; thus, further studies are needed. Clin Endosc 2021 Jul 7.

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