Ruiying Chen

Author directory

2026

Retrieval-Augmented Generation (RAG) is widely employed to mitigate risks such as hallucinations and knowledge obsolescence in medical question answering, yet its predominantly single-round, static retrieval paradigm misaligns with the multi-stage process of clinical reasoning. This compressed workflow induces two structural deficiencies: question-to-query translation often lacks clinically grounded semantic interpretation, and retrieval lacks iterative sufficiency feedback, making it difficult to form reliable evidence chains. We argue that both issues stem from a deeper cause—overloading a single reasoning chain with heterogeneous tasks of interpretation, exploration, and adjudication—and that the remedy is to reconstruct the workflow via task decoupling and dynamic multi-round exploration. To this end, we propose the Self-Evolving Multi-Agent framework SEMA-RAG, which assigns these roles to three specialist agents: Interpreter Agent for clinical schema interpretation, Explorer Agent for sufficiency-driven self-evolving retrieval, and Arbiter Agent for evidence adjudication and answer selection. Across five benchmarks and five LLM backbones, SEMA-RAG improves the strongest baseline by +6.46 accuracy points on average, measured per backbone.
Hallucination detection in clinical large vision-language models requires cross-verifying heterogeneous evidence, including patient text and images for faithfulness, and medical knowledge for factuality. However, existing pipelines either verify these dimensions in isolation or conflate them into a uniform process, potentially causing evidence misalignment that limits detection precision. Consequently, we posit that the essence of black-box hallucination detection is an evidence routing problem and propose MedF2Route, an Evidence-Routed Graph Verification Framework for both Faithfulness and Factuality hallucination detection. Specifically, it first transforms free-text clinical queries and model responses into structured graphs, partitioning the response graph into independent subgraphs to separate patient-specific grounding from knowledge-based diagnostic inference. An evidence-aware routing and verification mechanism then dynamically dispatches response triplets in these subgraphs to their dedicated heterogeneous evidence sources for targeted verification. Experiments on our MedF2Bench diagnostic benchmark show that our framework outperforms state-of-the-art baselines, notably improving detection precision. Overall, MedF2Route enables professional and precise detection of clinical hallucinations, underpinning the trustworthiness of clinical LVLMs. The code and data are available at https://github.com/Agentic-CliniAI/MedF2Route.