Ono, Shokoa1; Shimoda, Yoshihikob2; Tanaka, Ikkob2; Kinowaki, Sayokob2; Inoue, Masakib2; Ono, Masayoshib2; Yamamoto, Keikoc3; Shimizu, Yuichic3; Sakamoto, Naoya2
European Journal of Gastroenterology & Hepatology: September 9, 2020 – Volume Publish Ahead of Print – Issue –
Objective: Linked color imaging (LCI) enables noninvasive detection of gastric intestinal metaplasia (GIM) as a lavender color sign (LCS), and there has been a recent report that l-menthol enhanced GIM with LCI. We measured color values of GIM and surrounding mucosa with white light imaging (WLI), LCI and LCI after spraying l-menthol (Mint-LCI) and investigated the effect of l-menthol on gastric mucosa.
Methods: Endoscopic images of the antrum with WLI, LCI and Mint-LCI from 18 patients were prepared. Each of six regions of interest (three points of GIM and three points of surrounding mucosa) was selected for each modality, and CIE1976 (Lab) color space was used to measure the color values. The primary endpoint was color differences (ΔE) between GIM and surrounding mucosa in each modality. Results For surrounding mucosa, the mean a value with Mint-LCI was significantly higher than the mean values with WLI and LCI (P < 0.01). The mean b* value of GIM with LCI was significantly lower than that of surrounding mucosa, and spraying l-menthol decreased the b* values of GIM with a change to a deeper lavender color (LCI: 10.0 ± 5.8, Mint-LCI: 3.7 ± 6.1, P < 0.01). However, there was no significant difference in mean ΔE values between LCI and Mint LCI (LCI: 21.1 ± 6.6, Mint-LCI: 22.7 ± 5.4, NS). After spraying l-menthol, the microstructure of GIM changed to translucent and microvessels were obscured.
Conclusions: As shown by LCI, spraying l-menthol optically enhances the color of GIM in the antrum.
1 Department of Gastroenterology, Hokkaido University Hospital
2 Department of Gastroenterology and Hepatology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University
3 Division of Endoscopy, Hokkaido University Hospital, Sapporo, Japan