Suzuki T, Hara T etc

Gastrointest Endosc. 2017 Feb 10. pii: S0016-5107(17)30088-3. Impact factor 5.369

Background and Aims: As a newly developed image-enhanced endoscopy (IEE) technique, linked-color imaging (LCI) provides very bright images with enhanced color tones. With the objective of improving the detection rate of colorectal flat tumor lesions, which are difficult to detect, we examined the usefulness of LCI from the viewpoint of visibility.

Methods: Fifty-three consecutive nongranular flat tumors were used in this study. Endoscopic images were acquired by white-light imaging (WLI), blue-laser imaging (BLI)-bright, and LCI modes. For each lesion, we selected one image each acquired by WLI, BLI-bright, and LCI modes. Six endoscopists interpreted the images. Using a previously reported visibility scale, we scored the visibility level on a scale of 1 to 4.

Results: The mean visibility scores were 2.74 ± 1.08 for WLI, 2.94 ± 0.97 for BLI-bright, and 3.36 ± 0.72 for LCI. The score was significantly higher for BLI-bright compared with WLI (p<0.001), and again higher for LCI compared with BLI-bright (p<0.001). When comparing between experts and trainees, the corresponding scores of experts were 2.83 ± 1.06, 3.17 ± 0.88, and 3.40 ± 0.74, with a tendency similar to the scores of all endoscopists. For the trainees, there was no difference between the scores for WLI (2.65 ± 1.10) and BLI-bright (2.71 ± 1.00), but the score for LCI (3.31 ± 0.69) was significantly higher than that for WLI or BLI-bright (p<0.001). When only sessile serrated adenoma/polyp (SSA/P) lesions were analyzed, LCI remained significantly higher than the other two.

Conclusions: The present findings suggest that LCI increases the visibility of colorectal flat lesions and contributes to improve the detection rate of these lesions.

Sun X, Dong T

Sci Rep. 2016 Sep 19; Impact factor 5.228

Abstract: Endoscopy has been widely used in diagnosing gastrointestinal mucosal lesions. However, there are still lack of objective endoscopic criteria. Linked color imaging (LCI) is newly developed endoscopic technique which enhances color contrast. Thus, we investigated the clinical application of LCI and further analyzed pixel brightness for RGB color model. All the lesions were observed by white light endoscopy (WLE), LCI and blue laser imaging (BLI). Matlab software was used to calculate pixel brightness for red (R), green (G) and blue color (B). Of the endoscopic images for lesions, LCI had significantly higher R compared with BLI but higher G compared with WLE (all P < 0.05). R/(G + B) was significantly different among 3 techniques and qualified as a composite LCI marker. Our correlation analysis of endoscopic diagnosis with pathology revealed that LCI was quite consistent with pathological diagnosis (P = 0.000) and the color could predict certain kinds of lesions. ROC curve demonstrated at the cutoff of R/(G+B) = 0.646, the area under curve was 0.646, and the sensitivity and specificity was 0.514 and 0.773. Taken together, LCI could improve efficiency and accuracy of diagnosing gastrointestinal mucosal lesions and benefit target biopsy. R/(G + B) based on pixel brightness may be introduced as a objective criterion for evaluating endoscopic images.

Dohi O¹, Yagi N¹, etc

Endosc Int Open. 2016 Jul;4(7): Impact factor 5.196

Background and Study Aims: Linked color imaging (LCI) is a new image-enhanced endoscopy technique using a laser light source to enhance slight differences in mucosal color. The aim of this study was to compare the usefulness of LCI and conventional white light imaging (WLI) endoscopy for diagnosing Helicobacter pylori (H. pylori).

Patients and Methods: We retrospectively analyzed images from 60 patients examined with WLI and LCI endoscopy between October 2013 and May 2014. Thirty patients had H. pylori infections, and other thirty patients tested negative for H. pylori after eradication therapy. Four endoscopists evaluated the 2 types of images to determine which was better at facilitating a diagnosis of H. pylori infection.

Results: H. pylori infection was identified with LCI by enhancing the red appearance of the fundic gland mucosa. The accuracy, sensitivity, and specificity for diagnosing H. pylori infection using WLI were 74.2 %, 81.7 %, and 66.7 %, respectively, while those for LCI were 85.8 %, 93.3 %, and 78.3 %, respectively. Thus, the accuracy and sensitivity for LCI were significantly higher than those for WLI (P = 0.002 and P = 0.011, respectively). The kappa values for the inter- and intraobserver variability among the 4 endoscopists were higher for LCI than for WLI.

Conclusion: H. pylori infection can be identified by enhancing endoscopic images of the diffuse redness of the fundic gland using LCI. LCI is a novel image-enhanced endoscopy and is more useful for diagnosing H. pylori infection than is WLI.

Masahiro O, Hirotsugu S, etc

Clin Endosc. 2016 Mar; 49(2) Impact factor 0.94

A 66-year-old woman with a 40-mm laterally spreading tumor of the rectum was referred for endoscopic resection. Before the endoscopic resection, we observed the lesion with an EC-L590ZW endoscope with the LASEREO system (FUJIFILM Co., Tokyo, Japan), with white light (Fig. 1A) and with Linked Color Imaging (LCI) (Fig. 1B). The lesion was clearly seen as a bright reddish area on LCI. Compared with the white light image, the LCI image makes the lesion more easily recognizable, thanks to the striking color contrast between the neoplastic mucosa and the normal mucosa. The lesion was diagnosed as an adenoma on the basis of the magnified BLI images. Successful en bloc endoscopic submucosal dissection was performed for the lesion, and the diagnosis of high-grade adenoma with negative resection margins was confirmed histopathologically.

LCI may facilitate the detection of flat colorectal neoplasms without magnification. After the detection of lesions, BLI images are easily produced with a push of a button for use in qualitative diagnosis. Further studies are needed to confirm the utility of LCI.

Suzuki T¹, Hara T¹

Gastrointest Endosc. 2016 Oct;84(4): Impact factor 5.369

Background and Aims: Many reports have shown the usefulness of magnification endoscopy with crystal violet (CV) staining for delineating the pit pattern in the diagnosis of colorectal carcinoma. However, the diagnostic accuracy of this method is not adequate for assessing the depth of invasion of early stage cancers. The novel technology of linked color imaging (LCI) combined with CV staining is expected to improve the accuracy of determining the depth of invasion.

Methods: We studied 3 patients with early stage colorectal cancer who were referred to our hospital. After CV spraying, high-magnification endoscopy was conducted by using the LCI mode. Efficacy of this modality was evaluated by comparing the preoperative diagnostic endoscopic images with posttreatment histopathologic findings.

Results: In 2 cases of rectal cancer, although conventional endoscopic examination could not exclude the possibility of submucosal cancer, use of the LCI mode with CV staining confirmed mucosal cancer. Eventually, EMR was conducted and achieved curative resection. In 1 case of sigmoid colon cancer, both conventional and CV magnification endoscopy suggested submucosal cancer. However, mucosal cancer was diagnosed by the novel method, and EMR achieved curative resection.

Conclusions: LCI high-magnification endoscopy combined with CV staining provides images close to histopathologic findings and is expected to improve the accuracy of endoscopic diagnosis of the depth of invasion for early stage colorectal cancer.

Fukuda H, Miura Y et al

Clinical Journal of Gastroenterology. 2015 Dec;Volume 8, Issue 6, pp 385-389 Impact factor 3.186

Abstract: Conventional endoscopy can miss flat early gastric cancers (0-IIb) because they may not be visible. We treated a patient with synchronous flat early gastric cancers missed by conventional white-light endoscopy (WLE). A 74-year-old Japanese male was referred for endoscopic submucosal dissection (ESD) of a depressed-type early gastric cancer (0-IIc) on the posterior wall of the antrum. Linked color imaging (LCI) detected two flat reddish lesions (0-IIb) measuring 30 mm and 10 mm in diameter in the distal body and prepyloric area, respectively, which had not been detected by conventional WLE. LCI clearly demonstrated the line of demarcation between the malignant lesion and the surrounding mucosa without magnification. Flat early gastric cancers were suspected because both lesions had irregular surface patterns using magnifying blue laser imaging (BLI). An additional depressed lesion (0-IIc) was detected by laser WLE along the greater curvature in the antrum. Magnifying BLI suggested a malignant lesion. Histological examination of biopsy specimens revealed atypical glands in all four lesions. ESD of these lesions was performed. Pathological examination of the resected specimens confirmed well-differentiated adenocarcinoma localized to the mucosa in all four lesions. Flat early gastric cancers became clearly visible using new endoscopic technology.