Colorectal Polyp Classification from White-light Colonoscopy Images via Domain Alignment

TL;DR

This paper introduces a novel teacher-student framework that leverages NBI images during training to improve colorectal polyp classification from white-light colonoscopy images, enhancing accuracy and clinical applicability.

Contribution

It presents a domain alignment and contrastive learning-based approach for accurate polyp classification using only WL images at inference, along with a new paired dataset.

Findings

Achieved 5.6% higher accuracy than previous methods.

Outperformed existing models in quantitative and qualitative evaluations.

Enabled fast and accurate polyp classification using only WL images.

Abstract

Differentiation of colorectal polyps is an important clinical examination. A computer-aided diagnosis system is required to assist accurate diagnosis from colonoscopy images. Most previous studies at-tempt to develop models for polyp differentiation using Narrow-Band Imaging (NBI) or other enhanced images. However, the wide range of these models' applications for clinical work has been limited by the lagging of imaging techniques. Thus, we propose a novel framework based on a teacher-student architecture for the accurate colorectal polyp classification (CPC) through directly using white-light (WL) colonoscopy images in the examination. In practice, during training, the auxiliary NBI images are utilized to train a teacher network and guide the student network to acquire richer feature representation from WL images. The feature transfer is realized by domain alignment and contrastive learning. Eventually the final student network has the ability to extract aligned features from only WL images to facilitate the CPC task. Besides, we release the first public-available paired CPC dataset containing WL-NBI pairs for the alignment training. Quantitative and qualitative evaluation indicates that the proposed method outperforms the previous methods in CPC, improving the accuracy by 5.6%with very fast speed.