Miyaki R, Yoshida S, etc

J Clin Gastroenterol. 2015 Feb;49(2): Impact factor 3.186

Goals: To evaluate the usefulness of a newly devised computer system for use with laser-based endoscopy in differentiating between early gastric cancer, reddened lesions, and surrounding tissue.

Background: Narrow-band imaging based on laser light illumination has come into recent use. We devised a support vector machine (SVM)-based analysis system to be used with the newly devised endoscopy system to quantitatively identify gastric cancer on images obtained by magnifying endoscopy with blue-laser imaging (BLI). We evaluated the usefulness of the computer system in combination with the new endoscopy system.

Results: The average SVM output value was 0.846 ± 0.220 for cancerous lesions, 0.381 ± 0.349 for reddened lesions, and 0.219 ± 0.277 for surrounding tissue, with the SVM output value for cancerous lesions being significantly greater than that for reddened lesions or surrounding tissue. The average SVM output value for differentiated-type cancer was 0.840 ± 0.207 and for undifferentiated-type cancer was 0.865 ± 0.259.

Conclusions: Although further development is needed, we conclude that our computer-based analysis system used with BLI will identify gastric cancers quantitatively.

Nakano A¹, Hirooka Y², etc

Endosc Int Open. 2017 Apr;5(4): Impact factor 5.196

Background and Aim: There have been few evaluations of the diagnostic ability of new narrow band light observation blue laser imaging (BLI). The present prospective study compared the diagnostic ability of BLI magnification and pit pattern analysis for colorectal polyps.

Patients and Methods: We collected lesions prospectively, and the analysis of images was made by two endoscopists, retrospectively. A total of 799 colorectal polyps were examined by BLI magnification and pit pattern analysis at Nagoya University Hospital. The Hiroshima narrow-band imaging classification was used for BLI. Differentiation of neoplastic from non-neoplastic lesions and diagnosis of deeply invasive submucosal cancer (dSM) were compared between BLI magnification and pit pattern analysis. Type C2 in the Hiroshima classification was evaluated separately, because application of this category as an index of the depth of cancer invasion was considered difficult.

Results: We analyzed 748 colorectal polyps, excluding 51 polyps that were inflammatory polyps, sessile serrated adenoma/polyps, serrated adenomas, advanced colorectal cancers, or other lesions. The accuracy of differential diagnosis between neoplastic and non-neoplastic lesions was 98.4 % using BLI magnification and 98.7 % with pit pattern analysis. In addition, the diagnostic accuracy of BLI magnification and pit pattern analysis for dSM for cancer was 89.5 % and 92.1 %, respectively. When type C2 lesions were excluded, the diagnostic accuracy of BLI for dSM was 95.9 %. The 18 type C2 lesions comprised 1 adenoma, 9 intramucosal or slightly invasive submucosal cancers, and 8 dSM. Pit pattern analysis allowed accurate diagnosis of the depth of invasion in 13 lesions (72.2 %).

Conclusion: Most colorectal polyps could be diagnosed accurately by BLI magnification without pit pattern analysis, but we should add pit pattern analysis for type C2 lesions in the Hiroshima classification.

Kaneko K, Oono Y, etc

Endosc Int Open. 2014 Dec;2(4): Impact factor 5.196

Background and Aim: The novel method of image-enhanced endoscopy (IEE) named blue laser imaging (BLI) can enhance the contrast of surface vessels using lasers for light illumination. BLI has two IEE modes: high contrast mode (BLI-contrast) for use with magnification, and bright mode (BLI-bright), which achieves a brighter image than BLI-contrast and yet maintains the enhanced visualization of vascular contrast that is expected for the detection of tumors from a far field of view. The aim of this study is to clarify the effect of BLI-bright with a far field of view compared to BLI-contrast and commonly available narrow-band imaging (NBI).

Patients and Methods: Patients with neoplasia, including early cancer in the pharynx, esophagus, stomach, or colorectum, were recruited and underwent tandem endoscopy with BLI and NBI systems. Six sets of images of the lesions were captured with a changing observable distance from 3 to 40 mm. Individual sets of images taken from various observable distances were assessed for visibility among BLI-bright, BLI-contrast, and NBI modes. The brightness and contrast of these images were also analyzed quantitatively.

Results: Of 51 patients, 39 were assessed. Image analysis indicated that only BLI-bright maintained adequate brightness and contrast up to 40 mm and had significantly longer observable distances compared to the other methods. Furthermore, BLI-bright enhanced the visualization of serious lesions infiltrating into deeper layers, such as esophageal lamina propria or gastric submucosal cancers.

Conclusion: BLI-bright will be a helpful tool for the far-field view with IEE in organs with wider internal spaces such as the stomach.

Shimoda R, Sakata Y et al

Endoscopy. 2017 Feb;49(2):186-190.

Background/Aim: The aim of the present study was to determine whether blue-laser imaging (BLI) reduced the miss rate of colon adenomatous lesions compared with conventional white-light imaging (WLI).

Patients/Methods: This was a prospective randomized study of patients undergoing screening and/or surveillance colonoscopy at Saga Medical School, Japan. A total of 127 patients were randomized to tandem colonoscopy with BLI followed by WLI (BLI-WLI group) or WLI followed by WLI (WLI-WLI group). The main outcome measure was the adenoma miss rate.

Results: The proportion of patients with adenomatous lesions was 62.5 % (40 /64) in the BLI-WLI group and 63.5 % (40 /63) in the WLI-WLI group. The total number of adenomatous lesions detected in the first inspection of the BLI-WLI and WLI-WLI groups was 179 and 108, respectively, compared with 182 and 120 in the second inspection, respectively. The miss rate in the BLI-WLI group was (1.6 %), which was significantly less than that in the WLI-WLI group (10.0 %, P = 0.001).

Conclusion: Colonoscopy using BLI resulted in a lower colon adenoma miss rate than WLI.

BLI study pdf

Dohi O, Yagi N et all,

Gastric Cancer. 2016 Jun 13.

Background: Blue laser imaging (BLI) is a new image-enhanced endoscopy technique that utilizes a laser light source developed for narrow-band light observation. The aim of this study was to evaluate the usefulness of BLI for the diagnosis of early gastric cancer.

Methods: This single center prospective study analyzed 530 patients. The patients were examined with both conventional endoscopy with white-light imaging (C-WLI) and magnifying endoscopy with BLI (M-BLI) at Kyoto Prefectural University of Medicine between November 2012 and March 2015. The diagnostic criteria for gastric cancer using M-BLI included an irregular microvascular pattern and/or irregular microsurface pattern, with a demarcation line according to the vessel plus surface classification system. Biopsies of the lesions were taken after C-WLI and M-BLI observation. The primary end point of this study was to compare the diagnostic performance between C-WLI and M-BLI.

Results: We analyzed 127 detected lesions (32 cancers and 95 non-cancers). The accuracy, sensitivity, and specificity of M-BLI diagnoses were 92.1, 93.8, and 91.6 %, respectively. On the other hand, the accuracy, sensitivity, and specificity of C-WLI diagnoses were 71.7, 46.9, and 80.0 %, respectively.

Conclusions: M-BLI had improved diagnostic performance for early gastric cancer compared with C-WLI. These results suggested that the diagnostic effectiveness of M-BLI is similar to that of magnifying endoscopy with narrowband imaging (M-NBI).

Tahara T, Okubo M, et al

Gastrointestinal Endoscopy volume 83, 2016

Background/Aim: In the colorectum, lymphoid follicles hyperplasia (LH) are sometimes observed as small, round, yellowish-white nodules. The novel imageenhanced endoscopy system named blue laser imaging (BLI) provides enhanced the contrast of surface vessels using lasers for light illumination. The aim of the present study was to investigate endoscopic features of LH observed by BLI endoscopy and its association with chronic bowel symptoms in
healthy subjects.

Patients/ Methods: 300 healthy participants (median age: 60 years, male/ female: 180/120) undergoing screening colonoscopy were enrolled. After inserting colonoscope in to the cecum, entire colorectum was observed by using BLI-bright mode with non-magnification view. LH was defined as well demarcated white nodules. In particular, elevated LH with erythema was distinguished as LH high.

Results: LHs are observed more clearly by using BLI-bright mode than white light. LHs were histologically confirmed as intense infiltration of lymphocytes or plasmacytes. LH was observed in 134 subjects (44.6%). Among them, 67 (22.3%) was LH high. LH was associated younger age (Odds ratio (OR) = 1.05, 95%Confidence Interval (95%CI) = 1.03-1.07, P<0.0001). The location of LH was 25.3%, 37.7%, 15.3%, 14% 16.7%, and 15.7% in the cecum, ascending
colon transverse colon, descending colon, sigmoid colon and rectum, respectively. The presence of LH was significantly associated with chronic bowel symptoms including constipation, hard stools, diarrhea and loose stools (all LH: OR=4.03, 95%CI=2.36-6.89, P<0.0001, LH high: OR=5.31, 95%CI=2.64-10.71, P<0.0001). LH high was closely associated with both constipation associated symptoms (OR=3.94, 95%CI=1.79-8.66, P=0.0007) and diarrhea associated symptoms (OR=5.22, 95%CI=2.09-13.05, P=0.0004) . In particular, LH high in the ascending colon was strongly associated with bowel symptoms (P<0.0001).

Conclusion: LH, visualized by using BLI endoscopy was associated with bowel symptom, raising the possibility of pathogenic role of this endoscopic finding in the functional lower gastrointestinal disorders.