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arXiv 2603.04022cs.CV
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重新思考强化学习在放射学报告生成中的效率和有效性

Rethinking the Efficiency and Effectiveness of Reinforcement Learning for Radiology Report Generation

DAMO Academy, Alibaba Group(达摩院,阿里巴巴集团);Ningbo No.2 Hospital(宁波第二医院);Zhejiang University(浙江大学);Hupan Lab(华研实验室);Fudan University(复旦大学)

Zilin Lu, Ruifeng Yuan, Weiwei Cao, Wanxing Chang, Zhongyu Wei, Sinuo Wang, Yong Xia, Ling Zhang, Jianpeng Zhang

AI总结:

本文提出DiTPO方法,通过优化诊断F1分数提升放射学报告生成的临床准确性,实现更高效的数据利用和更优的性能表现。

摘要:

放射科医生高度希望实现完全自动化的AI用于放射学报告生成(R2G),但现有方法在临床实用性上仍有不足。强化学习(RL)有潜力解决这些不足,但其在该任务中的应用仍处于探索阶段。本文重新审视RL在R2G任务中的数据效率和优化有效性。首先,我们探讨数据数量和质量对RL在医疗环境中的性能影响,发现数据质量比数量更重要。为此,我们提出了一种基于诊断多样性的数据采样策略,使较少样本也能实现可比性能。其次,我们发现放射学报告中大多数token是模板化的且诊断信息不丰富,而临床关键token的低频率会增加被优化过程中忽视的风险。为此,我们引入了诊断token加权策略优化(DiTPO),通过使用诊断F1分数作为奖励信号,直接优化临床准确性。不同于标准RL方法将所有token同等对待,DiTPO通过规则或梯度机制明确建模不同token的重要性,优先考虑临床相关内容。在MIMIC-CXR、IU-Xray和CheXpert Plus数据集上的大量实验表明,我们的框架在要求较少训练样本的情况下实现了最先进的性能。值得注意的是,在MIMIC-CXR上,我们的框架仅使用20%的RL训练样本就达到了0.516的F1分数。

英文摘要:

Radiologists highly desire fully automated AI for radiology report generation (R2G), yet existing approaches fall short in clinical utility. Reinforcement learning (RL) holds potential to address these shortcomings, but its adoption in this task remains underexplored. In this paper, we revisit RL in terms of data efficiency and optimization effectiveness for R2G tasks. First, we explore the impact of data quantity and quality on the performance of RL in medical contexts, revealing that data quality plays a more critical role than quantity. To this end, we propose a diagnostic diversity-based data sampling strategy that enables comparable performance with fewer samples. Second, we observe that the majority of tokens in radiology reports are template-like and diagnostically uninformative, whereas the low frequency of clinically critical tokens heightens the risk of being overlooked during optimization. To tackle this, we introduce Diagnostic Token-weighted Policy Optimization (DiTPO), which directly optimizes for clinical accuracy by using a diagnostic F1 score as the reward signal. Unlike standard RL approaches that treat all tokens equally, DiTPO explicitly models the varying importance of different tokens through rule- or gradient-based mechanisms to prioritize clinically relevant content. Extensive experiments on the MIMIC-CXR, IU-Xray, and CheXpert Plus datasets demonstrate that our framework achieves state-of-the-art (SOTA) performance while requiring substantially fewer training samples in RL. Notably, on MIMIC-CXR, our framework attains an F1 score of 0.516 using only 20% of the RL training samples.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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