Medical visual question answering (MedVQA) requires models to provide accurate answers given a medical image and a corresponding question. Recently, instruction tuning of general large vision–language models (LVLMs) has become a dominant paradigm for this task, enabling open-ended predictions and effective integration of multimodal information. However, existing methods synthesize instruction data from image–caption pairs that primarily focus on visual attributes, rather than knowledge-level QA generation. This situation limits the model’s ability to learn relevant medical knowledge during training, thereby restricting its performance on MedVQA. Hence, this paper proposes MedKInstruct, which incorporates a multimodal medical knowledge graph (MMKG) to assist LVLMs in synthesizing knowledge-intensive instruction data. Additionally, we design an MMKG path–based reward function to train a stronger MedVQA model through reinforcement learning. Experimental results on the public datasets Slake and VQA-RAD show that MedKInstruct outperforms previous methods by 4.16% and 4.50%. The source code is available at the following link: https://github.com/Sonder-hang/MedKinstruct

Medical insurance plays a pivotal role in the healthcare system, where effective supervision relies on the precise execution of complex medical insurance rules. Existing solutions for medical insurance violation detection mainly rely on costly manual labor, limiting efficiency. Although current Large Language Models (LLMs) have demonstrated significant potential in general Natural Language Processing (NLP) tasks, they still struggle to understand these rules, and a corresponding evaluation benchmark is lacking. Hence, we propose T2ER, a benchmark to evaluate the capability of LLMs in converting texts into executable rules in medical insurance. T2ER consists of 2,115 rules and 5,636 synthetic Electronic Medical Record (EMR) test cases for execution verification. Furthermore, we design a dual evaluation framework spanning rule and execution levels to comprehensively assess transformation quality. We conduct extensive experiments on advanced LLMs. The results reveal a significant human-AI performance gap, indicating that this conversion remains a formidable challenge. The dataset is available at https://github.com/YHJ1223/T2ER.