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Quantitative Comparisons of Linked Color Imaging and White-Light Colonoscopy for Colorectal Polyp Analysis

Xinran Wei 1 , Jiyang Xie 1 , Wenrui He 1 , Min Min 2, Zhanyu Ma 1 and Jun Guo 1

The performance of imaging techniques has an important influence on the clinical diagnostic strategy of colorectal cancer. Linked color imaging (LCI) by laser endoscopy is a recently developed techniques, and its advantage in improving the analysis accuracy of colorectal polyps over white-light (WL) endoscopy has been demonstrated in previous clinical studies. However, there are no objective criteria to evaluate and compare the aforementioned endoscopy methods. This paper presents a new criterion, namely entropy of color gradients image (ECGI), which is based on color gradients distribution and provides a comprehensive and objective evaluating indicator of the performance of colorectal images. Our method extracts the color gradient image pairs of 143 colonoscopy polyps in the LCI-PairedColon database, which are generated with WL and LCI conditions, respectively. Then, we apply the morphological method to fix the deviation of light-reflecting regions, and the ECGI scores of sample pairs are calculated. Experimental results show that the average ECGI scores of LCI images (5.7071) were significantly higher than that of WL (4.6093). This observation is consistent with the clinical studies. Therefore, the effectiveness of the proposed criterion is demonstrated.

1 Pattern Recognition and Intelligent Systems Lab, Beijing University of Posts and Telecommunications, Beijing, China
2 Department of Gastroenterology and Hepatology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, China

Optical diagnosis of colorectal polyps with Blue Light Imaging using a new international classification

Sharmila Subramaniam1, Bu Hayee2, Patrick Aepli3, Erik Schoon4, Milan Stefanovic5, Kesavan Kandiah1, Sreedhari Thayalasekaran1, Asma Alkandari1, Paul Bassett6, Emmanuel Coron7, Oliver Pech8, Cesare Hassan9, Helmut Neumann10, Raf Bisschops11, Alessandro Repici12 and Pradeep Bhandari1

United European Gastroenterology Journal 0(0) 1–10 Received: 1 October 2018; accepted: 21 November 2018

Abstract Background: Blue Light Imaging (BLI) is a new imaging technology that enhances mucosal surface and vessel patterns. A specific BLI classification was recently developed to enable better characterisation of colorectal polyps (BLI Adenoma Serrated International Classification (BASIC)). The aim of this study was to validate the diagnostic performance of BASIC in predicting polyp histology in experienced and trainee endoscopists.

Methods: Five experienced and five trainee endoscopists evaluated high-definition white light (HDWL) and BLI images from 45 small polyps to assess baseline accuracy, sensitivity, specificity, and positive and negative predictive values (NPVs) of polyp histology. Each endoscopist was trained with the BLI classification before repeating the exercise. Results were compared pre- and post-training.

Results: The overall pre-training accuracy improved from 87% to 94%. The sensitivity and NPV of adenoma diagnosis also improved significantly from 79% to 96% and 81% to 95% with BASIC training. This improvement was noted in both groups. The interobserver level of agreement was very good (K=0.90) in the experienced cohort and good (K=0.66) in the trainee group post-training.

Conclusions: BLI is a useful tool for optical diagnosis, and the use of BASIC with adequate training can significantly improve the accuracy, sensitivity and NPV of adenoma diagnosis.

1 Department of Gastroenterology, Queen Alexandra Hospital, Portsmouth, Hampshire, UK
2 Department of Gastroenterology, King’s College Hospital NHS Foundation Trust, London, UK
3 Department of Gastroenterology, Luzerner Kantonspittal, Lucerne, Switzerland
4 Department of Gastroenterology, Catharina Hospital, Eindhoven, the Netherlands
5,Department of Gastroenterology, Diagnosticˇni center Bled, Ljubljana, Slovenia
6 StatsConsultancy Limited, Amersham, UK
7 Centre Hospitalier Universitaire and Faculte´ de Me´decine de Nantes, Institut des Maladies de l’Appareil Digestif, Nantes, France
8 Department of Gastroenterology and Interventional Endoscopy, St John of God Hospital, Regensburg, Bavaria, Germany
9 Department of Gastroenterology, Nuovo Regina Margherita Hospital, Rome, Italy
10 Department of Medicine, University Hospital Erlangen, Germany
11 Department of Gastroenterology and Hepatology, Universitaire Ziekenhuizen Leuven, Belgium
12 Istituto Clinico Humanitas, Rozzano, Lombardia, Italy

Blue Laser Imaging, Blue Light Imaging, and Linked Color Imaging for the Detection and Characterization of Colorectal Tumors.

Yoshida N 1 , Dohi O 1 , Inoue K 1 , Yasuda R 1 , Murakami T 1 , Hirose R 1 , Inoue K 1 , Naito Y 1 , Inada Y 2 , Ogiso K 3 , Morinaga Y 4 , Kishimoto M4 , Rani RA 5 , Itoh Y 1 .

Gut Liver. 2018 Dec 4. doi: 10.5009/gnl18276. [Epub ahead of print]

Abstract:A laser endoscopy system was developed in 2012. The system allows blue laser imaging (BLI), BLI-bright, and linked color imaging (LCI) to be performed as modes of narrow-band light observation; these modes have been reported to be useful for tumor detection and characterization. Furthermore, an innovative endoscopy system using four-light emitting diode (LED) multilight technology was released in 2016 to 2017 in some areas in which laser endoscopes have not been approved for use, including the United States and Europe. This system enables blue light imaging (this is also known as BLI) and LCI with an LED light source instead of a laser light source. Several reports have shown that these modes have improved tumor detection. In this paper, we review the efficacy of BLI and LCI with laser and LED endoscopes in tumor detection and characterization.

1 Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine
2 Department of Gastroenterology, Fukuchiyama City Hospital, Kyoto
3 Department of Gastroenterology, Osaka General Hospital of West Japan Railway Company, Osaka
4 Department of Surgical Pathology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
5 Gastroenterology Unit, Faculty of Medicine, Universiti Teknologi MARA, Shah Alam, Malaysia

Blue-light imaging has an additional value to white-light endoscopy in visualization of early Barrett’s neoplasia. an international multicenter cohort study.

de Groof AJ1, Swager A1, Pouw RE1, Weusten BLAM2, Schoon EJ3, Bisschops R4, Pech O5, Meining A6, Neuhaus H7, Curvers WL3, Bergman JJ1.

Gastrointest Endosc. 2018 Nov 9. pii: S0016-5107(18)33259-0. doi: 10.1016/j.gie.2018.10.046. [Epub ahead of print]

Background and aims: Endoscopic features of early neoplasia in Barrett’s esophagus (BE) are subtle. Blue-light imaging (BLI) may improve visualization of neoplastic lesions. The aim of this study was to evaluate BLI in visualization of Barrett’s neoplasia.

Methods: Corresponding white-light endoscopy (WLE) and BLI images of 40 BE lesions were obtained prospectively and assessed by 6 international experts in 3 assessments. Each assessment consisted of overview and magnification images. Assessments were as follows: Assessment 1: WLE only; Assessment 2: BLI only; and Assessment 3: corresponding WLE and BLI images. Outcome parameters were as follows: (1) appreciation of macroscopic appearance and surface relief (VAS-scores); (2) ability to delineate lesions (VAS-scores); (3) preferred technique for delineation (ordinal scores); and (4) quantitative agreement on delineations (AND/OR scores).

Results: Experts appreciated BLI significantly better than WLE for visualization of macroscopic appearance (median 8.0 vs 7.0, P<0.001) and surface relief (8.0 vs 6.0, P<0.001). For both overview and magnification images, experts appreciated BLI significantly better than WLE for ability to delineate lesions (8.0 vs 6.0, P<0.001 and 8.0 vs 5.0, P<0.001). There was no overall significant difference in AND/OR scores of WLE+BLI when compared with WLE, yet agreement increased significantly with WLE+BLI for cases with a low baseline AND/OR score on WLE, both in overview (mean difference 0.15, P=0.015) and magnification (mean difference 0.10, P=0.01).

Conclusions: BLI has additional value for visualization of BE neoplasia. Experts appreciated BLI better than WLE for visualization and delineation of BE neoplasia. Quantitative agreement increased significantly when BLI was offered next to WLE for lesions that were hard to delineate with WLE alone.

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 Department of Gastroenterology and Hepatology, University Hospitals Leuven, Leuven, Belgium
5 Gastroenterology and interventional Endoscopy, Krankenhaus Barmherzige Brüder, Regensburg, Germany.
6 Center of Internal Medicine, Ulm University, Ulm, Germany
7 Internal Medicine, Evangelisches Krankenhaus Düsseldorf, Düsseldorf, Germany

Leaving colorectal polyps in place can be achieved with high accuracy using blue light imaging (BLI).

Neumann H1, Neumann Sen H2, Vieth M3, Bisschops R4, Thieringer F1, Rahman KF1, Gamstätter T1, Tontini GE5, Galle PR1.

United European Gastroenterol J. 2018 Aug;6(7):1099-1105. doi: 10.1177/2050640618769731. Epub 2018 May 17.

Objectives: A negative predictive value of more than 90% is proposed by the American Society of Gastrointestinal Endoscopy Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) statement for a new technology in order to leave distal diminutive colorectal polyps in place without resection. To our knowledge, no prior prospective study has yet evaluated the feasibility of the most recently introduced blue light imaging (BLI) system for real-time endoscopic prediction of polyp histology for the specific endpoint of leaving hyperplastic polyps in place.

Aims: Prospective assessment of real-time prediction of colorectal polyps by using BLI.

Material and methods: In total, 177 consecutive patients undergoing screening or surveillance colonoscopy were included. Colorectal polyps were evaluated in real-time by using high-definition endoscopy and the BLI technology without optical magnification. Before resection, the endoscopist described each polyp according to size, shape and surface characteristics (pit and vascular pattern, colour and depression), and histology was predicted with a level of confidence (high or low).

Results: Histology was predicted with high confidence in 92.5% of polyps. Sensitivity of BLI for prediction of adenomatous histology was 92.68%, with a specificity and accuracy of 94.87 and 93.75%, respectively. Following the recommendation of the PIVI statement, positive and negative predictive values were calculated with values of 95 and 92.5%, respectively. Prediction of surveillance based on both US and European guidelines was correctly predicted in 91% of patients.

Conclusion: The most recently introduced BLI technology is accurate enough to leave distal colorectal polyps in place without resection. BLI also allowed for assignment of postpolypectomy surveillance intervals. This approach therefore has the potential to reduce costs and risks associated with the redundant removal of diminutive colorectal polyps.

1 First Medical Department, Interdisciplinary Endoscopy, University Medical Center Mainz, Mainz, Germany
2 Internistische Schwerpunktpraxis Bad Salzuflen, Germany
3 Institute of Pathology, Klinikum Bayreuth, Germany
4 Department of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium
5 Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Milan, Italy

Linked Color Imaging and Blue Laser Imaging for Upper Gastrointestinal Screening.

Osawa H1, Miura Y1, Takezawa T1, Ino Y1, Khurelbaatar T1, Sagara Y1, Lefor AK2, Yamamoto H1.

Clin Endosc. 2018 Nov 2. doi: 10.5946/ce.2018.132. [Epub ahead of print]

White light imaging (WLI) may not reveal early upper gastrointestinal cancers. Linked color imaging (LCI) produces bright images in the distant view and is performed for the same screening indications as WLI. LCI and blue laser imaging (BLI) provide excellent visibility of gastric cancers in high color contrast with respect to the surrounding tissue. The characteristic purple and green color of metaplasias on LCI and BLI, respectively, serve to increase the contrast while visualizing gastric cancers regardless of a history of Helicobacter pylori eradication.
LCI facilitates color-based recognition of early gastric cancers of all morphological types, including flat lesions or those in an H. pylori-negative normal background mucosa as well as the diagnosis of inflamed mucosae including erosions. LCI reveals changes in mucosal color before the appearance of morphological changes in various gastric lesions. BLI is superior to LCI in the detection of early esophageal cancers and abnormal findings of microstructure and microvasculature in close-up views of upper gastrointestinal cancers. Excellent images can also be obtained with transnasal endoscopy. Using a combination of these modalities allows one to obtain images useful for establishing a diagnosis. It is important to observe esophageal cancers (brown) using BLI and gastric cancers (orange) surrounded by intestinal metaplasia (purple) and duodenal cancers (orange) by LCI.

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