Aligning Human Knowledge with Visual Concepts Towards Explainable Medical Image Classification

TL;DR

This paper presents Explicd, a framework that enhances medical image classification explainability by integrating domain knowledge from language models and visual concepts, leading to better interpretability and performance.

Contribution

Introducing Explicd, a novel framework that fuses domain knowledge with visual concepts for explainable and improved medical image classification.

Findings

Explicd achieves state-of-the-art explainability on five benchmarks.

The framework improves classification accuracy over black-box models.

Explicd effectively incorporates expert knowledge into visual reasoning.

Abstract

Although explainability is essential in the clinical diagnosis, most deep learning models still function as black boxes without elucidating their decision-making process. In this study, we investigate the explainable model development that can mimic the decision-making process of human experts by fusing the domain knowledge of explicit diagnostic criteria. We introduce a simple yet effective framework, Explicd, towards Explainable language-informed criteria-based diagnosis. Explicd initiates its process by querying domain knowledge from either large language models (LLMs) or human experts to establish diagnostic criteria across various concept axes (e.g., color, shape, texture, or specific patterns of diseases). By leveraging a pretrained vision-language model, Explicd injects these criteria into the embedding space as knowledge anchors, thereby facilitating the learning of corresponding visual concepts within medical images. The final diagnostic outcome is determined based on the similarity scores between the encoded visual concepts and the textual criteria embeddings. Through extensive evaluation of five medical image classification benchmarks, Explicd has demonstrated its inherent explainability and extends to improve classification performance compared to traditional black-box models. Code is available at \url{https://github.com/yhygao/Explicd}.