Diagnostic value of i-Scan high definition endoscopy for screening polypoid lesions in right hemicolon / 中华消化内镜杂志

Objective To explore the diagnostic value of the i-Scan for detection of polypoid lesions in right hemicolon during colonoscopy. Methods A total of 200 patients who underwent colonoscopy in Beijing Shijitan Hospital from January 2015 to December 2015 were enrolled. After completion of the first colonoscopy in right hemicolon, a second withdrawal was performed, using white light mode ( white light group, n=93) and i-Scan mode ( i-scan group, n=96) to detect polypoid lesions in the proximal colon. The detection rates of polyp and adenoma were compared between the two groups. Results During the twice withdrawal, compared with white light group, more polyps and adenomas were detected in i-Scan group (1. 469 VS 1. 011, P=0. 028; 0. 979 VS 0. 624,P=0. 039). The proportion of patients with more polyps and adenomas in the i-Scan group was significantly higher than that in the white light group [ 37. 5％( 36/96) VS 22. 6％ ( 21/93) , P=0. 025;24. 0％ ( 23/96) VS 11. 8％ ( 11/93) ,P=0. 030] . i-Scan mode detected more small polyps with diameter<5 mm [ 84. 0％ ( 42/50 ) VS 58. 3％ ( 14/24 ) , P=0. 016 ] . However, there were no differences between the two groups in the size, location, and morphology of the detected adenomas ( all P>0. 05) . The polyp detection rates of the i-Scan group and white light group were 61. 5％ (59/96) and 48. 4％ (45/93), respectively (P=0. 071), and the adenoma detection rates were 47. 9％ (46/96) and 35. 5％ (33/93), respectively (P=0. 083). Conclusion I-Scan mode can increase the detection rate of polyps and adenomas in right hemicolon, and improve detection of polypoid lesions and bsmall polyps in patients with multiple polyps and adenomas.

La cromoendoscopia virtual i-Scan y su aplicación en la detección y caracterización de los pólipos de colon / Virtual Chromoendoscopy with I-Scan and its Application for Detection and Characterization of Colon Polyps

La limitación de la colonoscopia con luz blanca respecto a la omisión de neoplasias avanzadas en un 6%, y de adenomas hasta un 25%, ha motivado el desarrollo de técnicas como la cromoendoscopia virtual, entre ellas el sistema i-Scan, para detectar un mayor número de pólipos, como estrategia de prevención del cáncer de colon. Con esta revisión se resume la aplicación actual de este método en la detección de adenomas y su caracterización. Se ha encontrado que este nuevo sistema es una alternativa posible en nuestro medio a las ya existentes y mejor conocidas, como el NBI y FICE.

The limitations of white light colonoscopy result in missing 6% of advanced neoplasias in 6% and up to 25% of adenomas. This has motivated the development of techniques such as virtual chromoendoscopy including the i-Scan system to detect larger numbers of polyps as a strategy for preventing colon cancer. This review summarizes the current application of this technique for detection and characterization of adenomas. The new system is a possible alternative in our environment to the better known NBI and FICE which are already being used here

Increased Detection of Colorectal Polyps in Screening Colonoscopy Using High Definition i-SCAN Compared with Standard White Light

BACKGROUND/AIMS: The aim of this study was to evaluate the efficacy of high definition (HD) i-SCAN for colorectal polyp detection in screening colonoscopy. METHODS: We retrospectively analyzed the records of 501 patients who had undergone screening colonoscopy performed by three endoscopists with either HD i-SCAN (n=149) or standard white light (n=352) from January 2, 2014 through June 30, 2014. Patient information and inter-endoscopist variation as well as polyp number, endoscopic findings, and pathologic characteristics were reviewed. RESULTS: The detection rates of colorectal and neoplastic polyps were significantly higher using HD i-SCAN than standard white light colonoscopy (52% vs. 38.1%, p=0.004 for colorectal polyps; and 37.2% vs. 27.9%, p=0.041 for neoplastic polyps). Analysis of endoscopic findings revealed no difference in detected polyp size between HD i-SCAN and standard white light colonoscopy (4.59+/-2.35 mm vs. 4.82+/-2.81 mm, p=0.739), but non-protruding polyps were more commonly detected by i-SCAN than by standard white light colonoscopy (24.6% vs. 13.5%, p=0.007). CONCLUSIONS: Colonoscopy using HD i-SCAN had a significantly higher detection rate of colorectal polyps, including neoplastic polyps, because of improved sensitivity for detecting non-protruding lesions.

The Past, Present, and Future of Image-Enhanced Endoscopy

Despite the remarkable progress recently made to enhance the resolution of white-light endoscopy, detection, and diagnosis of premalignant lesions, such as adenomas and subtle early-stage cancers, remains a great challenge. As for example, although chromoendoscopy, such as endoscopy using indigo carmine, is useful for the early diagnosis of subtle lesions, the technique presents various disadvantages ranging from the time required for spray application of the dye and suctioning of excess dye to the increased difficulty in identifying lesions in the presence of severe inflammation and obstruction of visual field due to the pooling of solution in depressed-type lesions. To overcome these diagnostic problems associated with chromoendoscopy, research has focused on the development of endoscopes based on new optical technologies. Several types of image-enhanced endoscopy methods have recently been presented. In particular, image-enhanced endoscopy has emerged as a new paradigm for the diagnosis of gastrointestinal disorders. Image-enhanced endoscopes provide high-contrast images of lesions by means of optical or electronic technologies, including the contrast enhancement of the mucosal surface and of blood vessels. Chromoendoscopy, narrow-band imaging, i-SCAN, and flexible spectral imaging color enhancement are representative examples of image-enhanced endoscopy discussed in this paper.

Advanced Imaging Technology Other than Narrow Band Imaging

To improve the detection rate of gastrointestinal tumors, image-enhanced endoscopy has been widely used during screening and surveillance endoscopy in Korea. In addition to narrow band imaging (NBI) with/without magnification, various types of electronic chromoendoscopies have been used, including autofluorescence imaging, I-scan, and flexible spectral imaging color enhancement. These technologies enable the accurate characterization of tumors because they enable visualization of microvascular and microsurface patterns. The present review focuses on understanding the principle and clinical applications of advanced imaging technologies other than NBI.

Advances in the Endoscopic Assessment of Inflammatory Bowel Diseases: Cooperation between Endoscopic and Pathologic Evaluations

Endoscopic assessment has a crucial role in the management of inflammatory bowel disease (IBD). It is particularly useful for the assessment of IBD disease extension, severity, and neoplasia surveillance. Recent advances in endoscopic imaging techniques have been revolutionized over the past decades, progressing from conventional white light endoscopy to novel endoscopic techniques using molecular probes or electronic filter technologies. These new technologies allow for visualization of the mucosa in detail and monitor for inflammation/dysplasia at the cellular or sub-cellular level. These techniques may enable us to alter the IBD surveillance paradigm from four quadrant random biopsy to targeted biopsy and diagnosis. High definition endoscopy and dye-based chromoendoscopy can improve the detection rate of dysplasia and evaluate inflammatory changes with better visualization. Dye-less chromoendoscopy, including narrow band imaging, iScan, and autofluorescence imaging can also enhance surveillance in comparison to white light endoscopy with optical or electronic filter technologies. Moreover, confocal laser endomicroscopy or endocytoscopy have can achieve real-time histology evaluation in vivo and have greater accuracy in comparison with histology. These new technologies could be combined with standard endoscopy or further histologic confirmation in patients with IBD. This review offers an evidence-based overview of new endoscopic techniques in patients with IBD.

Efficacy of I-scan Endoscopy in the Diagnosis of Gastroesophageal Reflux Disease with Minimal Change

BACKGROUND/AIMS: The aim of the study was to evaluate the efficacy of i-scans for the diagnosis of gastroesophageal reflux disease, especially where only minimal change is involved. METHODS: The esophageal mucosa was inspected using an i-scan following conventional white light endoscopy. The examination with iscan was performed under tone enhancement (TE) esophagus (e) mode. Patients with subtle distal esophageal mucosal changes without definite mucosal breaks, such as blurring of Z-line (B), mucosal coarseness (C), hyperemic or purplish discoloration (D), erythema (E), ectopic gastric mucosal islet (I) and mixed type were classified as minimal change. RESULTS: A total of 156 patients were included. Using i-scan endoscopy, the number of minimal change was found to further increase from 94 (conventional endoscopy; 19B, 9C, 29D, 13E, 5I, 19 mixed type) to 109 (i-scan; 15B, 8C, 29D, 16E, 5I, 36 mixed type). And 14 patients who had single type by conventional endoscopy were converted to mixed type after i-scan. Therefore, 29 of 156 patients were upgraded after i-scan, they were account for 19% (p<0.0001; 95% confidence interval, 0.13 to 0.25). CONCLUSIONS: The use of i-scan endoscopy significantly improves the identification of minimal change and helps to identify more precisely the type of minimal change.

Efficacy of I-scan Endoscopy in the Diagnosis of Gastroesophageal Reflux Disease with Minimal Change

BACKGROUND/AIMS: The aim of the study was to evaluate the efficacy of i-scans for the diagnosis of gastroesophageal reflux disease, especially where only minimal change is involved. METHODS: The esophageal mucosa was inspected using an i-scan following conventional white light endoscopy. The examination with iscan was performed under tone enhancement (TE) esophagus (e) mode. Patients with subtle distal esophageal mucosal changes without definite mucosal breaks, such as blurring of Z-line (B), mucosal coarseness (C), hyperemic or purplish discoloration (D), erythema (E), ectopic gastric mucosal islet (I) and mixed type were classified as minimal change. RESULTS: A total of 156 patients were included. Using i-scan endoscopy, the number of minimal change was found to further increase from 94 (conventional endoscopy; 19B, 9C, 29D, 13E, 5I, 19 mixed type) to 109 (i-scan; 15B, 8C, 29D, 16E, 5I, 36 mixed type). And 14 patients who had single type by conventional endoscopy were converted to mixed type after i-scan. Therefore, 29 of 156 patients were upgraded after i-scan, they were account for 19% (p<0.0001; 95% confidence interval, 0.13 to 0.25). CONCLUSIONS: The use of i-scan endoscopy significantly improves the identification of minimal change and helps to identify more precisely the type of minimal change.

Digital chrome endoscopy and confocai laser endomicroscopy in diagnosis of Barrett esophagus / 中华消化内镜杂志

ObjectiveTo evaluate digital chrome endoscopy (I-Scan) and confocal laser endomicroscopy (CLE) for diagnosis of Barrett esophagus (BE).MethodsFrom July 2010 to July 2011,a total of 878 outpatients who had upper gastrointestinal symptoms underwent routine endoscopy and I-Scan examination,screened patients with suspected Barrett's epithelial were further referred to CLE and endoscopy.The detection rate and image features of BE between routine endoscopy and I-Scan,and the diagnosis of BE between pathology and CLE,were compared respectively.ResultsSuspected BE was diagnosed in 46 patients (5.2％) by routine endoscopy,and in52 (5.9％) by I-Scan,and there was no significant difference in detection rate between 2 methods (x2 =0.533,P ＞ 0.05 ).The detection rate of paliform blood vessels between SCJ and GEJ was higher using I-Scan (35/52,67.3％ ) than routine endoscope (21/46,45.7％,P ＜0.05).A total of 19 suspected BE underwent CLE and biopsy,and BE was diagnosed by CLE with a sensitivity of 93％ and a specificity of 100％.ConclusionI-Scan is capable of identifying paliform blood vessels between SCJ and GEJ,and can improve the detection rate of suspected BE.CLE is able to provide in-vivo histological diagnosis of BE with a high sensitivity and specificity.

Recent Advances in Image-enhanced Endoscopy

The desire to better recognized such malignancies, which may be difficult to distinguish from inflammation or trauma, has accelerated the development of endoscopy with new optical technologies. Narrow-band imaging is a novel endoscopic technique that may enhance the accuracy of diagnosis using narrow-bandwidth filters in a red-green-blue sequential illumination system. Autofluorescence imaging is based on the detection of natural tissue fluorescence emitted by endogenous molecules. I-scan technology using a digital filter that modifies normal images through software functions, is the newly developed image-enhanced endoscopic technology from PENTAX. Flexible spectral imaging color enhancement enhances the visualization of mucosal structure and microcirculation by the selection of spectral transmittance with a dedicated wavelength. Confocal laser endomicroscopy images were collected with an argon beam with a scanning depth of 0 (epithelium) to 250 microm (lamina propria) and analyzed using the reflected light.

The Current Status of Virtual Chromoscopy / 대한소화기내시경학회지

Virtual chromoscopy is a novel technology that enhances endoscopic visualization of superficial mucosal surfaces and microvascular architecture. Currently available virtual chromoscopy techniques include narrow band imaging, Fujinon intelligent color enhancement and I-scan. Refinements are expected to improve detection of the lesions, which will lead to further insight into the pathological processes, in turn, providing guidance in selecting the optimal treatment. Presently, we review the currently available literature regarding virtual chromoscopy and provide technical principles, clinical usefulness, and limitations.