Chen TH^1,2, Hsu CM¹, Cheng HT¹, Chu YY¹, Su MY¹, Hsu JT³, Yeh TS³, Kuo CF⁴, Chiu CT¹.

J Chin Med Assoc. 2018 May 16. pii: S1726-4901(18)30096-0. doi: 10.1016/j.jcma.2018.03.006. [Epub ahead of print]

Background: Esophagogastroduodenoscopy (EGD) is a standard tool for detection of mucosal and submucosal lesions. However, identification of Helicobacter pylori (H. P) infection using EGD alone is limited in accuracy. Linked color imaging (LCI) is a novel tool to capture real-time image with sufficient contrast to observe mucosal microstructure.

Methods: This study aims to evaluate the applicability of LCI in the identification of H. pylori infection. Consecutive 122 patients scheduled for EGD were included. They were examined with LCI and magnifying endoscopy. The classification of H. pylori was based on pathology results of biopsy and rapid urease test or urea breath test.

Results: We compared the results based on LCI or magnifying endoscopy to reference classification. Of 122 patients, 36 had H. pylori infection (29.51%). The level of accuracy of diagnosis of H. pylori infections by LCI, magnifying endoscopy, and both LCI and magnifying endoscopy was 78.38%, 81.98%, and 78.38%, respectively. The sensitivity and specificity of each group were 70.97%, 81.25%, and 80.65% and 82.5%, 83.87%, and 76.25%, respectively. The positive predictive values were 59.46%, 64.10%, and 57.78%, respectively, and the negative predictive values were 87.84%, 91.67%, and 92.42%, respectively.

Conclusion: LCI could be playing a valuable initial screen tool for real-time diagnosis of H. pylori infections. It has a high accuracy of diagnosis of H. pylori infections. Therefore, in patients suspected to have H. pylori infections using LCI, the infections need to be carefully diagnosed using appropriate methods because, as per the consensus, they should be eradicated as soon as possible before precancerous lesions develop.

1 Department of Gastroenterology and Hepatology, Chang Gung Memorial Hospital- Linkou and Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC
2 Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan, ROC
3 Department of Surgery, Chang Gung Memorial Hospital-Linkou and Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC
4 Division of Rheumatology, Allergy, and Immunology, Chang Gung Memorial Hospital- Linkou and Chang Gung University College of Medicine, Taoyuan,Taiwan, ROC

Paggi S¹, Mogavero G¹, Amato A¹, Rondonotti E¹, Andrealli A¹, Imperiali G¹, Lenoci N¹, Mandelli G¹, Terreni N¹, Conforti FS¹, Conte D¹, Spinzi G¹, Radaelli F¹.

Endoscopy. 2018 Apr;50(4):396-402. doi: 10.1055/a-0580-7405. Epub 2018 Mar 14.

Background:  Linked color imaging (LCI) is a newly developed image-enhancing endoscopy technology that provides bright endoscopic images and increases color contrast. We investigated whether LCI improves the detection of neoplastic lesions in the right colon when compared with high definition white-light imaging (WLI).

Methods: Consecutive patients undergoing colonoscopy were randomized (1:1) after cecal intubation into right colon inspection at first pass by LCI or by WLI. At the hepatic flexure, the scope was reintroduced to the cecum under LCI and a second right colon inspection was performed under WLI in previously LCI-scoped patients (LCI–WLI group) and vice versa (WLI–LCI group). Lesions detected on first- and second-pass examinations were used to calculate detection and miss rates, respectively. The primary outcome was the right colon adenoma miss rate.

Results: Of the 600 patients enrolled, 142 had at least one adenoma in the right colon, with similar right colon adenoma detection rates (r-ADR) in the two groups (22.7 % in LCI–WLI and 24.7 % in WLI–LCI). At per-polyp analysis, double inspection of the right colon in the LCI–WLI and WLI–LCI groups resulted in an 11.8 % and 30.6 % adenoma miss rate, respectively (P < 0.001). No significant difference in miss rate was found for advanced adenomas or sessile serrated lesions. At per-patient analysis, at least one adenoma was identified in the second pass only (incremental ADR) in 2 of 300 patients (0.7 %) in the LCI – WLI group and in 13 of 300 patients (4.3 %) in the WLI – LCI group (P = 0.01).

Conclusions: LCI could reduce the miss rate of neoplastic lesions in the right colon.

^{1 Division of Digestive Endoscopy and Gastroenterology, Valduce Hospital, Como, Italy.
# Contributed equally}

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.}