Takeda T¹, Nagahara A², Ishizuka K¹, Okubo S¹, Haga K¹, Suzuki M¹, Nakajima A¹, Komori H¹, Akazawa Y¹, Izumi K¹, Matsumoto K¹, Ueyama H¹, Shimada Y¹, Matsumoto K¹, Asaoka D¹, Shibuya T¹, Sakamoto N¹, Osada T¹, Hojo M¹, Nojiri S³, Watanabe S¹.

Digestion. 2018 Jan 10;97(2):183-194. doi: 10.1159/000485459. [Epub ahead of print]

Background/Aims: To evaluate the usefulness of linked color imaging (LCI) and blue LASER imaging (BLI) in Barrett’s esophagus (BE) compared with white light imaging (WLI).

Methods: Five expert and trainee endoscopists compared WLI, LCI, and BLI images obtained from 63 patients with short-segment BE. Physicians assessed visibility as follows: 5 (improved), 4 (somewhat improved), 3 (equivalent), 2 (somewhat decreased), and one (decreased). Scores were evaluated to assess visibility. The inter- and intra-rater reliability (intra-class correlation coefficient) of image assessments were also evaluated. Images were objectively evaluated based on L* a* b* color values and color differences (ΔE*) in a CIELAB color space system.

Results: Improved visibility compared with WLI was achieved for LCI: 44.4%, BLI: 0% for all endoscopists; LCI: 55.6%, BLI: 1.6% for trainees; and LCI: 47.6%, BLI: 0% for experts. The visibility score of trainees compared with experts was significantly higher for LCI (p = 0.02). Intra- and inter-rater reliability ratings for LCI compared with WLI were “moderate” for trainees, and “moderate-substantial” for experts. The ΔE* revealed statistically significant differences between WLI and LCI.

Conclusion: LCI improved the visibility of short-segment BE compared with WLI, especially for trainees, when evaluated both subjectively and objectively.

^{1 Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan.
2 Department of Gastroenterology, Juntendo Sizuoka Hospital, Sizuoka, Japan.
3 Department of Medical Technology Innovation Center, Juntendo University School of Medicine, Tokyo, Japan.}

Mizukami K¹, Ogawa R¹, Okamoto K¹, Shuto M¹, Fukuda K¹, Sonoda A¹, Matsunari O¹, Hirashita Y¹, Okimoto T¹, Kodama M¹, Murakami K¹.

Gastroenterol Res Pract. 2017; 2017:5054237. Epub 2017 Nov 15.

Objectives: We aimed to determine whether linked color imaging (LCI), a new image-enhanced endoscopy that enhances subtle differences in mucosal colors, can distinguish the border of endoscopic mucosal atrophy.

Methods: This study included 30 patients with atrophic gastritis. In endoscopy, we continuously took images in the same composition with both LCI and white light imaging (WLI). In each image, the color values of atrophic and nonatrophic mucosae were quantified using the International Commission on Illumination 1976 (L∗, a∗, b∗) color space. Color differences at the atrophic border, defined as Euclidean distances of color values between the atrophic and nonatrophic mucosae, were compared between WLI and LCI for the overall cohort and separately for patients with Helicobacter pylori infection status.

Results: We found that the color difference became significantly higher with LCI than with WLI in the overall samples of 90 points in 30 patients. LCI was 14.79 ± 6.68, and WLI was 11.06 ± 5.44 (P < 0.00001). LCI was also more effective in both of the Helicobacter pylori-infected group (P = 0.00003) and the Helicobacter pylori-eradicated group (P = 0.00002).

Conclusions: LCI allows clear endoscopic visualization of the atrophic border under various conditions of gastritis, regardless of Helicobacter pylori infection status.

^{1 Department of Gastroenterology, Oita University, Japan.}

Hisamatsu T¹, Ohno A¹, Chiba T².

Dig Endosc. 2017 Nov 27. doi: 10.1111/den.12992. [Epub ahead of print]

Ulcerative colitis (UC) associated colorectal cancer (CRC) is an important issue in long-term management of patients with UC. Lesions with chronic inflammatory mucosa as background may often be difficult to identify even by endoscopic observation. Traditionally, a random biopsy strategy was recommended, but problems with patient compliance, increased burden on endoscopic staff and pathologists, were left. This article is protected by copyright. All rights reserved.

^{1 Third Department of Internal Medicine, Kyorin University School of Medicine.
2 Department of Pathology, Kyorin University School of Medicine.}

Wu CH^1,2, Chen TH^1,2,3, Hsu CM^1,2, Su MY^1,2, Chiu CT^1,2, Wu RC⁴, Lai CC⁵.

Ther Clin Risk Manag. 2017 Oct 3;13:1317-1321.

Introduction: Linked-color imaging (LCI) is a recently developed system used in endoscopy. It creates clear and bright endoscopic images using short-wavelength, narrow-band laser light combined with white laser light. The illuminating light and signal processing emphasize slight color differences in abnormal regions that approximate the normal color of the mucosa. As a result, regions initially appearing red become a deeper shade of red, while regions originally appearing white become brighter, yet with natural tones. This process facilitates recognition of slight differences in the color of the mucosa and clarifies the boundaries of the mucosal pit.

Aim: To determine whether LCI of the colon can improve the correlation between endoscopic findings and pathological diagnosis.

Methods: Consecutive patients who underwent colonoscopy requiring polypectomy or removal by biopsy forceps if possible were recruited. Probable polyp histology was assessed by two endoscopists using the Narrow-band imaging International Colorectal Endoscopic (NICE) classification and LCI data. All detected polyps were sent to the pathology department for pathological diagnosis by two pathologists.

Results: In total, 94 polyps were found in 43 patients. The sensitivity, specificity, positive predictive value, and negative predictive value for neoplastic lesion prediction (NICE type2/3) were 96.5%, 83.8%, 90.2%, and 93.9%, respectively.

Conclusion: LCI combined with the NICE classification system is a powerful tool for predicting probable histology of colon polyps.

^{1 Department of Gastroenterology and Hepatology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan.
2 Chang Gung University, College of Medicine, Taoyuan.
3 Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan.
4 Department of Pathology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan.
5 Department of Colon and Rectal Surgery, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan.}