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Blue laser imaging and linked color imaging improve the color difference value and visibility of colorectal polyps in underwater conditions.

Yamasaki Y1, Harada K1, Yamamoto S1, Yasutomi E1, Okanoue S1, Hirai M1, Oka S1, Obayashi Y1, Sakae H1, Hamada K1, Inokuchi T1, Kinugasa H1, Sugihara Y1, Takahara M1, Tanaka T2, Hiraoka S1, Kawahara Y1, Okada H1.

Dig Endosc. 2019 Nov 23. doi: 10.1111/den.13581. [Epub ahead of print]

Background and aim: Underwater endoscopic mucosal resection (UEMR) has become widespread for treating colorectal polyps. However, which observational mode is best suited for determining polyp margins underwater remains unclear. To determine the best mode, we analyzed three imaging modes: white light imaging (WLI), blue laser imaging (BLI) and linked color imaging (LCI).

Methods: Images of consecutive colorectal polyps previously examined via these three modes before UEMR were analyzed according to the degree of turbidity underwater (transparent or cloudy). Color differences between the polyps and their surroundings were calculated using the Commission Internationale d’Eclairage Lab color space in which three-dimensional color parameters were expressed. Eight evaluators, who were blinded to the histology, scored the visibility from one (undetectable) to four (easily detectable) in both underwater conditions. The color differences and visibility scores were compared.

Results: Seventy-three polyps were evaluated. Sixty-one polyps (44 adenomatous, 17 serrated) were observed under transparent conditions, and 12 polyps (7 adenomatous, 5 serrated) were observed under cloudy conditions. Under transparent conditions, the color differences for the BLI (8.5) and LCI (7.9) were significantly higher than that of the WLI (5.7; P <.001). The visibility scores for the BLI (3.6) and LCI (3.4) were also higher than that of the WLI (3.1; P<.0001). Under cloudy conditions, the visibility scores for LCI (2.9) and WLI (2.7) were significantly higher than that of the BLI (2.2; P<.0001 and P=0.04, respectively).

Conclusions: BLI and LCI were the better observational modes in transparent water; however, BLI was unsuitable for cloudy conditions.

1 Department of Gastroenterology, Okayama University Hospital, Okayama, Japan
2 Department of Pathology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan

Comparison Between Linked Color Imaging and Blue Laser Imaging for Improving the Visibility of Flat Colorectal Polyps: A Multicenter Pilot Study.

Yoshida N 1, Hisabe T2, Ikematsu H3, Ishihara H2, Terasawa M2, Inaba A3, Sato D3, Cho H4, Ego M4, Tanaka Y4, Yasuda R1, Inoue K1, Murakami T1, Inada Y1, Itoh Y1, Saito Y4.

Dig Dis Sci. 2019 Nov 14. doi: 10.1007/s10620-019-05930-x. [Epub ahead of print]

Introduction: Linked color imaging (LCI) and blue laser imaging-bright (BLI-b) improve the visibility of gastrointestinal lesions. In this multicenter study, we compared the effects of LCI and BLI-b on the visibility of flat polyps with visibility scores and color difference (CD) values, including fast-withdrawal and large-monitor observation.

Methods: We recorded 120 videos of 40 consecutive flat polyps (2-20 mm), adenoma, and sessile serrated adenoma and polyp (SSA/P), using white light imaging (WLI), BLI-b, and LCI from July 2017 to December 2017. All videos were evaluated by eight endoscopists according to a published polyp visibility score of 4 (excellent) to 1 (poor). Additionally, 1.5 ×faster and 1.7 ×sized videos were evaluated. Moreover, we calculated the CD values for each polyp in three modes.

Results: The mean LCI scores (3.1 ± 0.9) were significantly higher than the WLI scores (2.5 ± 1.0, p < 0.001) but not significantly higher than the BLI-b scores (3.0 ± 1.0). The scores of faster videos on LCI (3.0 ± 1.1) were significantly higher than WLI (2.0 ± 1.0, p < 0.001) and BLI-b (2.8 ± 1.1, p = 0.03). The scores of larger-sized videos on LCI were not significantly higher than those of WLI or BLI-b. The CD value of LCI (18.0 ± 7.7) was higher than that of WLI (11.7 ± 7.0, p < 0.001), but was not significantly higher than that of BLI-b (16.6 ± 9.6). The CD value of LCI was significantly higher than that of BLI-b for adenoma, but the CD value of BLI-b was significantly higher than that of LCI for SSA/P.

Conclusions: The superiority of LCI to BLI-b was proven for the visibility of adenoma and fast observation

1 Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
2 Department of Gastroenterology, Fukuoka University Chikushi Hospital, Fukuoka, Japan
3 Department of Gastroenterology and Endoscopy, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
4 Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan

The Color Difference between Differentiated Early Gastric Cancer and Suspicious Mucosal Areas on Linked Color Imaging.

Kanzaki H1, Kawahara Y2, Okada H1.

Digestion. 2019 Nov 13:1-6. doi: 10.1159/000503958. [Epub ahead of print]

Background: Image enhanced endoscopy (IEE) contributes to the early detection of gastrointestinal cancer. IEE enhances the color between a lesion and the background mucosa. Linked color imaging (LCI), a novel form of IEE, is a unique system for enhancing color and some studies have demonstrated the efficacy of LCI in the diagnosis of early gastric cancer (EGC) based on the color difference between cancer and the background mucosa. However, the effect may increase the area in which cancer is suspected and lead to an increase in false-positive results.

Summary: We conducted a retrospective study of linked color images of differentiated EGC and suspicious mucosal areas to compare the colors between each lesion. Images of 38 EGCs and 23 suspicious areas were analyzed. The mean color values of EGC were as follows; L(lightness), 61.7; a(green to red), 41.2; and b(blue to yellow), 27.1. Those of suspicious mucosal areas were as follows; L, 56.1; a, 44.2; and b, 21.3. EGC had significantly higher L, b values and lower a* values in comparison to suspicious mucosal areas. EGC and suspicious mucosal areas had significantly higher a* values in comparison to the background mucosa.

Key Messages: EGC had higher b* values in comparison to suspicious mucosal areas, and was not only reddish but also mixed with yellow, with an orange-like color.

1 Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Denistry and Pharmaceutical Sciences, Okayama, Japan
2 Department of Practical Gastrointestinal Endoscopy, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan

Linked color imaging for the detection of early gastrointestinal neoplasms.

Shinozaki S1, Osawa H1, Hayashi Y1, Lefor AK2, Yamamoto H1.

Therap Adv Gastroenterol. 2019 Nov 1;12:1756284819885246. doi: 10.1177/1756284819885246. eCollection 2019.

In routine upper and lower gastrointestinal endoscopy, overlooking neoplastic lesions is inevitable even for well-trained endoscopists. Various methods have been reported to improve the detection of gastrointestinal neoplasms including chromoendoscopy, special endoscopes, and processor and image enhanced technologies. Equipment-based image enhanced endoscopy (e-IEE) using narrow band imaging (NBI) and blue laser imaging (BLI) is useful to characterize known lesions with magnification at a close-up view. However, they are not useful for the early detection of superficial, pale neoplasms, or both because of the weak image at a distant view in a wide lumen such as the stomach or colon. Linked color imaging (LCI) is a novel pre- and post-processing technology developed by Fujifilm Corporation that has sufficient brightness to illuminate a wide lumen. LCI delineates early gastric cancers as orange-red and intestinal metaplasia as purple. LCI improves the adenoma detection rate in the colon and decreases the polyp miss rate. LCI contributes to the detection of superficial lesions throughout the gastrointestinal tract by enhancing the color contrast between the neoplasm and the surrounding mucosa. LCI can distinguish them by their specific color allocation based mainly on the distribution of capillaries. The authors believe that moving forward, LCI should be used in routine upper and lower gastrointestinal endoscopy.

1 Department ofMedic ine, Division of Gastroenterology, Jichi Medical University, Shimotsuke, Japan
2 Department of Surgery, Jichi Medical University, Shimotsuke, Japan


Reliability and accuracy of blue light imaging for staging of intestinal metaplasia in the stomach.

Castro R1, Rodriguez M1, Libânio D1,2, Esposito G3, Pita I1, Patita M4, Santos C2,5, Pimentel-Nunes P1,5,6, Dinis-Ribeiro M1,2,5.

Scand J Gastroenterol. 2019 Nov 3:1-5. doi: 10.1080/00365521.2019.1684555. [Epub ahead of print]

Background and aims: An endoscopic grading system (EGGIM) using narrow-band-imaging (NBI) has shown to accurately identify patients with extensive gastric intestinal metaplasia (GIM). However, description with alternative systems such as blue-light-imaging (BLI) is limited. The aim of this study is to determine the reliability and accuracy of BLI-bright regarding diagnosis and staging of GIM.

Methods: Reliability of WLE (white-light-endoscopy) and BLI among 6 observers was assessed using a standard classification based on endoscopic images. Afterward, 37 patients were submitted to gastroscopy using FujifilmEG-760Z and endoscopists had to determine EGGIM score using BLI-bright and to perform gastric biopsies for operative-link-of-gastric-intestinal-metaplasia (OLGIM) calculation. BLI-bright accuracy was determined by comparing results with prior EGGIM scores with NBI and current OLGIM.

Results: Compared with WLE, the interobserver reliability between observers was substantially better with BLI (Weighted Kappa: 0.8 vs 0.41). There was an 84% agreement between BLI and NBI assessing EGGIM intervals (EGGIM 0-4vs5-10). The area under the ROC curve was 0.90 (95%CI: 0.79-1.0) using the cut-off of EGGIM > 4 to determine advanced GIM, with a sensitivity of 100% (95%CI: 88-100%).

Discussion: BLI-bright is reliable for the diagnosis of gastric intestinal metaplasia and agrees significantly with NBI evaluation. Preliminary data suggests high sensitivity for identifying patients with increased risk of gastric cancer.

1 Gastroenterology Department, Oncology Portuguese Institute of Porto, Porto, Portugal
2 Faculty of Medicine, CINTESIS, University of Porto, Porto, Portugal
3 Department of Medical-Surgical Sciences and Translational Medicine, Sant’Andrea Hospital, Sapienza University of Rome, Rome, ltaly
4 Gastroenterology Department, Hospital Garcia de Orta, Almada, Portugal
5 Faculty of Medicine, MEDCIDS, University of Porto, Porto, Portugal
6 Faculty of Medicine, Department of Surgery and Physiology, University of Porto, Porto, Portugal

Additional value of linked color imaging in colonoscopy: a retrospective study.

Sakamoto T1, Tomizawa 1,2, Cho H1, Takamaru H1, Sekiguchi M1, Yamada M1,3, Matsuda T1, Murakami Y4, Saito Y1.

Endosc Int Open. 2019 Nov;7(11):E1448-E1454. doi: 10.1055/a-0982-2904. Epub 2019 Oct 22.

Background and study aims: Linked color imaging (LCI), a newly developed optical modality, enhances mucosal surface contrast. We aimed to evaluate the efficacy and feasibility of insertion-phase LCI in terms of additional benefit of colorectal polyp detection over that obtained with white light imaging (WLI).

Patients and methods: We consecutively enrolled eligible patients from November 2017 to June 2018. During colonoscopy, LCI or WLI was alternatively applied on scope insertion and LCI was applied on scope withdrawal. Patients were divided into two groups according to the protocolized difference of imaging modality used in the scope insertion phase (LCI and WLI groups). Group differences in clinical outcomes were evaluated.

Results: A total of 138 patients were enrolled in this study, with equal numbers of patients assigned to the LCI and WLI groups. Most of the lesions located in the proximal colon were detected during the withdrawal phase, without a difference in proportions between the two groups. However, in the LCI group, eight of 49 lesions (16 %) located in the sigmoid and rectosigmoid colon were only detected during the insertion phase, and no such lesions (0 %) were detected during the insertion phase in the WLI group ( P  = 0.045).

Conclusions: This study showed the efficacy and feasibility of LCI in improving colorectal polyp detection in the sigmoid colon, especially during insertion. Further studies are warranted to validate the results of our single-center study.

1 Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan
2 Gastroenterology, Harborview Medical Center, Seattle, Washington, United States
3 Division of Molecular Modification and Cancer Biology, National Cancer Center Research Institute, Tokyo, Japan
4 Department of Medical Statistics, Toho University, Tokyo, Japan