Linked color imaging improves visibility of colorectal serrated lesion by high color contrast to surrounding mucosa.

Abstract

This study aimed to objectively evaluate the efficacy of linked color imaging (LCI) in diagnosing colorectal serrated lesions by utilizing visibility scores and color differences. We examined 89 serrated lesions, including 36 hyperplastic polyps (HPs), 47 sessile serrated lesions (SSLs), and six traditional serrated adenomas (TSAs). Visibility changes were scored by six endoscopists as follows: 4, excellent; 3, good; 2, fair; and 1, poor. Furthermore, images obtained by white-light imaging (WLI) or LCI were assessed using the CIELAB color space in the lesion and adjacent mucosa. We calculated the mean color values (L*, a*, and b*) measured at five regions of interest of the sample lesion and surrounding mucosa and derived the color difference (ΔE*). The visibility scores of both HPs and SSLs in LCI were significantly higher than that in WLI (HPs, 3.67/2.89, P < 0.001; SSLs, 3.07/2.36, P < 0.001). Furthermore, SSLs showed a significantly higher L* value and significantly lower a* and b* values in LCI than the adjacent mucosae (L*, 61.76/58.23, P = 0.016; a*, 14.91/17.58, P = 0.019; b*, 20.42/24.21, P = 0.007), while WLI produced no significant difference in any color value. A similar trend was apparent in HPs. In all serrated groups, LCI revealed significantly greater ΔE* values between the lesion and adjacent mucosa than WLI (HPs, 11.54/6.12; SSLs, 13.43/7.67; TSAs, 35.00/22.48). Linked color imaging showed higher color contrast between serrated lesions and the surrounding mucosae compared with WLI, indicating improved visibility of colorectal serrated lesion using LCI.