Abstract:

Objective To investigate the clinical application of LASEREO endoscopic system in laterally spreading tumor（LST）. Methods Patients who underwent blue laser imaging ⁃bright（BLI ⁃bright）mode，linked color imaging（LCI）mode and white light imaging（WLI）mode of LASEREO colonoscopy from May 2017 to December 2021 at Fuding Hospital Affiliated to Fujian University of Traditional Chinese Medicine were retrospective analyzed. Among 76 patients，the male to female ratio was 45 to 31 with a median age of 72 years. Subjective visibility analy⁃ sis was performed by 6 endoscopists and divided into 2 groups（experts and trainees groups）with 3 endoscopists for each group.The main observation index was the visibility score（ranking score，RS）. The objective color difference （ΔE）between LST and surrounding mucosa in 3 modes were analyzed by using the L*a*b* color space. Results （1）The RS score of WLI，BLI⁃bright and LCI were（3.27 ± 0.48），（3.05 ± 0.59）and（3.42 ± 0.30），respectively. The RS score of LCI was significantly higher than BLI⁃bright（t = 5.286，P < 0.001）and WLI（t = 2.647，P = 0.010）， while BLI⁃bright was significantly lower than WLI（t = 2.289，P = 0.025）. When we compared between experts and trainees groups，there was no significant difference in experts group（F = 1.126，P = 0.326）；for trainees group， the RS score of LCI（3.32 ± 0.41）was significantly higher than BLI⁃bright（2.64 ± 0.85）（t = 6.19，P < 0.001）andWLI（3.01 ± 0.69）（t = 3.715，P < 0.001）（. 2）The color difference（ΔE）of WLI，BLI⁃bright and LCI were 16.8 ± 6.91，11.32 ± 3.17，and 27.21 ± 7.57，respectively. The color difference（ΔE）of LCI was significantly higher than BLI ⁃bright（t = 30.934，P < 0.001）and WLI（t = 61.411，P < 0.001），while BLI ⁃bright was significantly lower than WLI（t = 12.404，P < 0.001）. Moreover，the difference in brightness（ΔL），red⁃green components（Δa）and yellow⁃blue components（Δb）of LCI were all significantly higher than BLI⁃bright and WLI（P < 0.001），while BLI⁃ bright were all significantly lower than WLI（P < 0.05）. The color difference（ΔE）is mainly produced by red⁃green components（Δa）and yellow ⁃ blue components（Δb）in WLI and LCI，while produced by red ⁃ green components （Δa）in BLI⁃bright. Conclusion LCI mode of LASEREO endoscopic system can effectively improve LST visibility and color difference between LST and surrounding mucosa，LCI is more conducive to the detection of LST for the trainees，which is worthy of clinical application.

Key words: colonic neoplasms,  , laterally spreading tumor linked color imaging,  , blue light imaging ? bright