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

Abstract

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 (DE*). 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 DE* 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.

Linked-color imaging with or without artificial intelligence for adenoma detection: a randomized trial

“…with WLI [27]. In this study, LCI was used for both groups; however, there was a significant difference in SSL detection, suggesting they can be missed in endoscopy, even with LCI and improved visibility.…”

“…Furthermore, SSLs have poor vascularization, and LCI facilitates their diagnosis by increasing the whiteness in regions with insufficient vascularization 25 26 . One study showed that LCI yielded significantly higher visibility scores for both hyperplastic polyps and SSLs compared with white-light imaging 27 . In the current study, LCI was used for both groups; however, there was a significant difference in SSL detection, suggesting they can be missed in endoscopy, even with LCI and improved visibility.…”

Detecting colorectal lesions with image-enhanced endoscopy: an updated review from clinical trials

“…LCI improves the visibility of colorectal serrated lesions by increasing the color difference of the ΔE* scale between serrated lesions and the surrounding mucosae in images compared with WLE. 56 The color difference consists of lightness, red/green coordinates, and yellow/blue coordinates, and the calculated color difference is defined as ΔE*. Li et al 57 reported a parallel RCT that enrolled 884 patients and compared the SSL detection rate between LCI and WLE.…”

Efficacy of texture and color enhancement imaging for the visibility and diagnostic accuracy of non‐polypoid colorectal lesions

“…CD values can be calculated using the three attributes of color: lightness, chroma, and hue, and they have been positively correlated with increased polyp visibility. 16 , 17 , 18 The color in the images was evaluated using the International Commission on Illumination L*a*b* (CIELAB) color space system, 19 which is a three‐dimensional space for presenting a color with axes of L* (from black to white; white is highest), a* (from green to red; red is highest), and b* (from blue to yellow; yellow is highest). The distance between two points in the CIELAB color space is proportional to the difference in color perception.…”