Tsutomu Takeda¹, Daisuke Asaoka², Daiki Abe¹, Maiko Suzuki², Yuta Nakagawa², Hitoshi Sasaki², Yoshihiro Inami², Muneo Ikemura¹, Hisanori Utsunomiya¹, Shotaro Oki¹, Nobuyuki Suzuki¹, Atsushi Ikeda¹, Noboru Yatagai¹, Hiroyuki Komori¹, Yoichi Akazawa¹, Kohei Matsumoto¹, Kumiko Ueda¹, Hiroya Ueyama¹, Yuji Shimada¹, Kenshi Matsumoto¹, Mariko Hojo¹, Taro Osada¹, Shuko Nojiri³, Akihito Nagahara¹

BMC Gastroenterol. 2020 Oct 27;20(1):356. doi: 10.1186/s12876-020-01511-9.

Background: With more prevalent gastroesophageal reflux disease comes increased cases of Barrett’s esophagus and esophageal adenocarcinoma. Image-enhanced endoscopy using linked-color imaging (LCI) differentiates between mucosal colors. We compared LCI, white light imaging (WLI), and blue LASER imaging (BLI) in diagnosing reflux esophagitis (RE).

Methods: Consecutive RE patients (modified Los Angeles [LA] classification system) who underwent esophagogastroduodenoscopy using WLI, LCI, and BLI between April 2017 and March 2019 were selected retrospectively. Ten endoscopists compared WLI with LCI or BLI using 142 images from 142 patients. Visibility changes were scored by endoscopists as follows: 5, improved; 4, somewhat improved; 3, equivalent; 2, somewhat decreased; and 1, decreased. For total scores, 40 points was considered improved visibility, 21-39 points was comparable to white light, and < 20 points equaled decreased visibility. Inter- and intra-rater reliabilities (Intra-class Correlation Coefficient [ICC]) were also evaluated. Images showing color differences (ΔE) and L a* b* color values in RE and adjacent esophageal mucosae were assessed using CIELAB, a color space system.

Results: The mean age of patients was 67.1 years (range: 27-89; 63 males, 79 females). RE LA grades observed included 52 M, 52 A, 24 B, 11 C, and 3 D. Compared with WLI, all RE cases showed improved visibility: 28.2% (40/142), LA grade M: 19.2% (10/52), LA grade A: 34.6% (18/52), LA grade B: 37.5% (9/24), LA grade C: 27.3% (3/11), and LA grade D: 0% (0/3) in LCI, and for all RE cases: 0% in BLI. LCI was not associated with decreased visibility. The LCI inter-rater reliability was “moderate” for LA grade M and “substantial” for erosive RE. The LCI intra-rater reliability was “moderate-substantial” for trainees and experts. Color differences were WLI: 12.3, LCI: 22.7 in LA grade M; and WLI: 18.2, LCI: 31.9 in erosive RE (P < 0.001 for WLI vs. LCI).

Conclusion: LCI versus WLI and BLI led to improved visibility for RE after subjective and objective evaluations. Visibility and the ICC for minimal change esophagitis were lower than for erosive RE for LCI. With LCI, RE images contrasting better with the surrounding esophageal mucosa were more clearly viewed.

1 Department of Gastroenterology, Juntendo University School of Medicine,2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
2 Department of Gastroenterology, Juntendo Tokyo Koto Geriatric Medical Center, Tokyo, Japan.
3 Department of Medical Technology Innovation Center, Juntendo University School of Medicine, Tokyo, Japan.