LLM-RadJudge: Achieving Radiologist-Level Evaluation for X-Ray Report Generation
Zilong Wang, Xufang Luo, Xinyang Jiang, Dongsheng Li, Lili Qiu
TL;DR
This work introduces LLM-RadJudge, an evaluation framework that leverages large language models to assess radiology reports with radiologist-level alignment. It demonstrates that GPT-4, with a two-stage prompting strategy, achieves Kendall's tau around $0.735$, closely matching radiologist judgments and outperforming conventional metrics. To address cost and speed, the authors construct a large-scale dataset from LLM evaluations and distill the capability into smaller models (notably BioMistral-7B), achieving $ au \,\approx\,0.749$ while offering faster inference. The approach enables practical, scalable evaluation of radiology report generation and is intended to be open-sourced, facilitating broader adoption and ongoing improvements in clinically relevant model development.
Abstract
Evaluating generated radiology reports is crucial for the development of radiology AI, but existing metrics fail to reflect the task's clinical requirements. This study proposes a novel evaluation framework using large language models (LLMs) to compare radiology reports for assessment. We compare the performance of various LLMs and demonstrate that, when using GPT-4, our proposed metric achieves evaluation consistency close to that of radiologists. Furthermore, to reduce costs and improve accessibility, making this method practical, we construct a dataset using LLM evaluation results and perform knowledge distillation to train a smaller model. The distilled model achieves evaluation capabilities comparable to GPT-4. Our framework and distilled model offer an accessible and efficient evaluation method for radiology report generation, facilitating the development of more clinically relevant models. The model will be further open-sourced and accessible.
