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Publications on Blue Laser / BLI

Blue-light imaging and linked-color imaging improve visualization of Barrett’s neoplasia by nonexpert endoscopists.

de Groof AJ1, Fockens KN1, Struyvenberg MR1, Pouw RE1, Weusten BLAM2, Schoon EJ3, Mostafavi N4, Bisschops R5, Curvers WL3, Bergman JJ1.

Gastrointest Endosc. 2020 Jan 2. pii: S0016-5107(19)32579-9. doi: 10.1016/j.gie.2019.12.037. [Epub ahead of print]

Background and aims: Endoscopic recognition of early Barrett’s neoplasia is challenging. Blue-light imaging (BLI) and linked-color imaging (LCI) may assist endoscopists in appreciation of neoplasia. Our aim was to evaluate BLI and LCI for visualization of Barrett’s neoplasia in comparison with WLE alone, when assessed by nonexpert endoscopists.

Methods: In this web-based assessment, corresponding white-light endoscopy (WLE), BLI, and LCI images of 30 neoplastic Barrett’s lesions were delineated by 3 expert endoscopists to establish ground truth. These images were then scored and delineated by 76 nonexpert endoscopists from 3 countries and with different levels of expertise, in 4 separate assessment phases with a washout period of 2 weeks. Assessments were as follows: Assessment 1: WLE only; Assessment 2: WLE+BLI; Assessment 3: WLE+LCI; Assessment 4: WLE+BLI+LCI. The outcomes were (1) appreciation of macroscopic appearance and ability to delineate lesions (VAS-scores); (2) preferred technique (ordinal scores); and (3) assessors’ delineation performance in terms of overlap with expert ground truth.

Results: Median VAS scores for phases 2 to 4 were significantly higher than in phase 1 (P < 0.001). Assessors preferred BLI and LCI over WLE for appreciation of macroscopic appearance (P < 0.001) and delineation (P < 0.001). Linear mixed-effect models showed that delineation performance increased significantly in phase 4.

Conclusions: The use of BLI and LCI has significant additional value for the visualization of Barrett’s neoplasia, when used by nonexpert endoscopists. Assessors appreciated the addition of BLI and LCI better than the use of WLE alone. This addition furthermore led to improved delineation performance, thereby allowing for better targeted biopsy acquisition.

1 Department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.
2 Department of Gastroenterology and Hepatology, St. Antonius Hospital, Nieuwegein, the Netherlands.
3 Department of Gastroenterology and Hepatology, Catharina Hospital, Eindhoven, the Netherlands.
4 Biostatistical unit, department of Gastroenterology and Hepatology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
5 Department of Gastroenterology and Hepatology, University Hospitals Leuven, Leuven, Belgium

Computer-aided classification of colorectal polyps using blue-light and linked-color imaging

Thom Scheeve1, Ramon-Michel Schreuder2, Fons van der Sommen1, Joep E. G. IJspeert3, Evelien Dekker3, Erik J. Schoon2; Peter H. N. De With1

SPIE medical imaging, 13 March 2019

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Since most CRCs develop from colorectal polyps (CRPs), accurate endoscopic differentiation facilitates decision making on resection of CRPs, thereby increasing cost-efficiency and reducing patient risk. Current classification systems based on whitelight imaging (WLI) or narrow-band imaging (NBI) have limited predictive power, or they do not consider sessile serrated adenomas/polyps (SSA/Ps), although these cause up to 30% of all CRCs. To better differentiate adenomas, hyperplastic polyps, and SSA/Ps, this paper explores the feasibility of two approaches: (1) an accurate computer-aided diagnosis (CADx) system for automated diagnosis of CRPs, and (2) novel endoscopic imaging techniques like blue-light imaging (BLI) and linked-color imaging (LCI). Two methods are explored to predict histology: (1) direct classification using a support vector machine (SVM) classifier, and (2) classification via a clinical classification model (WASP classification) combined with an SVM. The use of probabilistic features of SVM facilitates objective quantification of the detailed classification process. Automated differentiation of colonic polyp subtypes reaches accuracies of 78−96%, thereby improving medical expert results by 4−20%. Diagnostic accuracy for directly predicting adenomatous from hyperplastic histology reaches 93% and 87−90% using NBI and the novel BLI and LCI techniques, respectively, thus improving medical expert results by 26% and 20−23%, respectively. Predicting adenomatous histology in diminutive polyps with high confidence yields NPVs of 100%, clearly satisfying the PIVI guideline recommendation on endoscopic innovations (≥90% NPV). Our CADx system outperforms clinicians, while the novel BLI technique adds performance value.

1 Eindhoven University of Technology, PO Box 513, Eindhoven, The Netherlands
2 Catharina Hospital, PO Box 1350, Eindhoven, The Netherlands
3 Amsterdam UMC, University of Amsterdam, PO Box 22660, Amsterdam, The Netherlands

Diagnostic Ability of Magnifying Blue Light Imaging with a Light Emitting Diode Light Source for Early Gastric Cancer: A Prospective Comparative Study.

Takayama S1, Dohi O1, Naito Y1, Azuma Y1, Ishida T1, Kitae H1, Matsumura S1, Ogita K1, Mizuno N1, Terasaki K1, Nakano T1, Ueda T1, Morinaga Y2, Hirose R1, Inoue K1, Yoshida N1, Kamada K1, Uchiyama K1, Ishikawa T1, Takagi T1, Handa O1,3, Kishimoto M2, Konishi H1, Itoh Y1.

Digestion. 2019 Dec 12:1-10. doi: 10.1159/000505018. [Epub ahead of print]

Introduction: An innovative endoscopic system using 4-color light-emitting diodes (LED) was released between 2016 and 2017 in locations that had not approved laser endoscopes for use, including the United States and Europe.

Objective: This study compared the diagnostic efficacy between magnifying blue light imaging with an LED light source (LED-BLI) and magnifying blue laser imaging with a laser light source (Laser-BLI) for early gastric cancer (EGC).

Methods: In this prospective, single-center, noninferiority study, 80 gastric lesions were evaluated between January 2017 and July 2017. The magnifying findings of gastric lesions – including the demarcation line (DL), microvascular pattern (MVP), and microsurface pattern (MSP) – were evaluated using Laser-BLI and LED-BLI according to the vessel plus surface classification system (VSCS). The primary end point was to determine whether the diagnostic accuracy of LED-BLI for EGC was noninferior to that of conventional Laser-BLI.

Results: Overall, we evaluated 79 gastric lesions histopathologically diagnosed as adenocarcinomas from the specimens obtained via endoscopic submucosal dissection. A DL was observed by Laser-BLI and LED-BLI in 98.7% (78/79) and 96.2% (76/79) of EGCs, respectively. The MVP observed using Laser-BLI and LED-BLI was irregular in 92.4% (73/79) and 89.9% (71/79), respectively. The MSP observed using Laser-BLI and LED-BLI was irregular in 83.5% (66/79) and 82.2% (65/79), respectively. According to the VSCS, diagnosable cancers were found in 94.9% (75/79) and 93.7% (74/79) of cases when using Laser-BLI and LED-BLI, respectively (p = 0.73; difference ratio, 1.2%; 95% CI -8.5 to 6.0%).

Conclusion: LED-BLI could accurately visualize the DL, MVP, and MSP of EGCs and was not inferior to Laser-BLI. Therefore, LED-BLI can be used to diagnose EGC accurately according to the VSCS-based diagnosis criteria

1 Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
2 Department of Surgical Pathology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
3 Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan

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

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