Colorectal mucosal exposure area assessment using artificial intelligence: a multicenter prospective observational study

Abstract

Background

This study proposed a new quality control indicator for colonoscopy, the cumulative colorectal mucosal exposure area (CCMEA), to assess mucosal exposure, constructed a CCMEA system based on deep learning, and validated the indicator in a multicenter prospective observational study.

Methods

The CCMEA system was based on ResNet50 and UNet++. A CCMEA threshold was determined on the basis of an adenoma detection rate (ADR) of 25%. A multicenter prospective observational study was conducted to evaluate the system and the threshold in clinical practice. Based on the CCMEA threshold, patients were divided into qualified and unqualified colonoscopy groups. The ADR and other lesion detection rates were then compared between the two groups.

Results

510 participants who underwent colonoscopy were evaluated, being grouped as having qualified (n = 270) or unqualified (n = 240) colonoscopies based on a CCMEA qualification threshold of 2000. The ADR was 39.5 percentage points higher in the qualified group than in the unqualified group (53.7% vs. 14.2%; adjusted odds ratio [aOR] 8.0, 95%CI 5.0–12.8; P < 0.001), and notably was higher for lesions ≤5 mm (42.2% vs. 10.0%; aOR 6.9, 95%CI 4.1–11.5; P < 0.001). The qualified group also had a significantly higher polyp detection rate (89.6% vs. 40.0%; aOR 13.1, 95%CI 7.8–21.8; P < 0.001) and higher mean numbers of both adenomas (1.0 vs. 0.2; adjusted incident rate ratio [aIRR] 5.9, 95%CI 4.3–8.4; P < 0.001) and polyps (5.8 vs. 1.3; aIRR 4.0, 95%CI 3.5–4.5; P < 0.001).

Conclusions

The CCMEA qualified group, based on a CCMEA threshold of 2000, showed a higher ADR than the unqualified group, indicating CCMEA could be a promising colonoscopy quality indicator.

Publication History

Received: 24 March 2025

Accepted after revision: 29 August 2025

Accepted Manuscript online:
03 September 2025

Article published online:
17 October 2025

• References

• 1 Pilonis ND, Bugajski M, Wieszczy P. et al. Long-term colorectal cancer incidence and mortality after a single negative screening colonoscopy. Ann Intern Med 2020; 173: 81-91
• 2 Hassan C, Antonelli G, Dumonceau JM. et al. Post-polypectomy colonoscopy surveillance: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2020. Endoscopy 2020; 52: 687-700
• 3 Anderson R, Burr NE, Valori R. Causes of post-colonoscopy colorectal cancers based on World Endoscopy Organization system of analysis. Gastroenterology 2020; 158: 1287-1299.e2
• 4 Rutter MD, Beintaris I, Valori R. et al. World Endoscopy Organization consensus statements on post-colonoscopy and post-imaging colorectal cancer. Gastroenterology 2018; 155: 909-925.e3
• 5 Zhou W, Yao L, Wu H. et al. Multi-step validation of a deep learning-based system for the quantification of bowel preparation: a prospective, observational study. Lancet Digit Health 2021; 3: e697-e706
• 6 Gong D, Wu L, Zhang J. et al. Detection of colorectal adenomas with a real-time computer-aided system (ENDOANGEL): a randomised controlled study. Lancet Gastroenterol Hepatol 2020; 5: 352-361
• 7 Lui TKL, Ko MKL, Liu JJ. et al. Artificial intelligence-assisted real-time monitoring of effective withdrawal time during colonoscopy: a novel quality marker of colonoscopy. Gastrointest Endosc 2024; 99: 419-427.e6
• 8 Yao L, Zhang L, Liu J. et al. Effect of an artificial intelligence-based quality improvement system on efficacy of a computer-aided detection system in colonoscopy: a four-group parallel study. Endoscopy 2022; 54: 757-68
• 9 Gong R, Yao L, Zhang L. et al. Complementary effect of the proportion of overspeed frames of withdrawal and withdrawal time on reflecting colonoscopy quality: a retrospective, observational study. Clin Transl Gastroenterol 2023; 14: e00566
• 10 Yao L, Li X, Wu Z. et al. Effect of artificial intelligence on novice-performed colonoscopy: a multicenter randomized controlled tandem study. Gastrointest Endosc 2024; 99: 91-99.e9
• 11 Kaminski MF, Regula J, Kraszewska E. et al. Quality indicators for colonoscopy and the risk of interval cancer. NEJM 2010; 362: 1795-1803
• 12 Kaminski MF, Wieszczy P, Rupinski M. et al. Increased rate of adenoma detection associates with reduced risk of colorectal cancer and death. Gastroenterology 2017; 153: 98-105
• 13 le Clercq CM, Bouwens MW, Rondagh EJ. et al. Postcolonoscopy colorectal cancers are preventable: a population-based study. Gut 2014; 63: 957-963
• 14 Liu W, Wu Y, Yuan X. et al. Artificial intelligence-based assessments of colonoscopic withdrawal technique: a new method for measuring and enhancing the quality of fold examination. Endoscopy 2022; 54: 972-979
• 15 Rex DK, Anderson JC, Butterly LF. et al. Quality indicators for colonoscopy. Am J Gastroenterol 2024; 119: 1754-1780
• 16 Lee RH, Tang RS, Muthusamy VR. et al. Quality of colonoscopy withdrawal technique and variability in adenoma detection rates (with videos). Gastrointest Endosc 2011; 74: 128-134
• 17 Barclay RL, Vicari JJ, Doughty AS. et al. Colonoscopic withdrawal times and adenoma detection during screening colonoscopy. NEJM 2006; 355: 2533-2541
• 18 Lee TJ, Blanks RG, Rees CJ. et al. Longer mean colonoscopy withdrawal time is associated with increased adenoma detection: evidence from the Bowel Cancer Screening Programme in England. Endoscopy 2013; 45: 20-26
• 19 Adler A, Wegscheider K, Lieberman D. et al. Factors determining the quality of screening colonoscopy: a prospective study on adenoma detection rates, from 12,134 examinations (Berlin colonoscopy project 3, BECOP-3). Gut 2013; 62: 236-241
• 20 Gellad ZF, Weiss DG, Ahnen DJ. et al. Colonoscopy withdrawal time and risk of neoplasia at 5 years: results from VA Cooperative Studies Program 380. Am J Gastroenterol 2010; 105: 1746-1752
• 21 Moritz V, Bretthauer M, Ruud HK. et al. Withdrawal time as a quality indicator for colonoscopy – a nationwide analysis. Endoscopy 2012; 44: 476-481
• 22 Rex DK, Sagi SV, Kessler WR. et al. A comparison of 2 distal attachment mucosal exposure devices: A noninferiority randomized controlled trial. Gastrointest Endosc 2019; 90: 835-840.e1
• 23 Triantafyllou K, Polymeros D, Apostolopoulos P. et al. Endocuff-assisted colonoscopy is associated with a lower adenoma miss rate: a multicenter randomized tandem study. Endoscopy 2017; 49: 1051-1060