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

Objectives: 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. Methods: 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 (Delta E*). Results: 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 Delta E* values between the lesion and adjacent mucosa than WLI (HPs, 11.54/ 6.12; SSLs, 13.43/7.67; TSAs, 35.00/22.48). Conclusion: 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.