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arXiv 2604.13331cs.LG

基于大语言模型的文本属性知识图谱增强用于医学概念表示

Text-Attributed Knowledge Graph Enrichment with Large Language Models for Medical Concept Representation

University of Kansas, USA(堪萨斯大学)

Mohsen Nayebi Kerdabadi, Arya Hadizadeh Moghaddam, Chen Chen, Dongjie Wang, Zijun Yao

AI总结:

本文提出MedCo框架,通过结合统计关联和LLM提示构建医学知识图谱,并利用LLM生成节点描述和边解释,最终融合文本语义与图结构生成统一的概念嵌入,提升临床预测性能。

摘要:

在电子健康记录(EHR)挖掘中,学习高质量的医学概念表示(如标准化诊断、药物和手术代码)对于下游临床预测至关重要。然而,稳健的概念表示学习受到两个关键挑战的阻碍:(i)临床重要的跨类型依赖(如诊断-药物和药物-手术关系)常在现有本体资源中缺失或不完整,限制了复杂EHR模式的建模能力;(ii)丰富的临床语义常缺失于结构化资源中,即使以文本形式存在,也难以与KG结构整合用于表示学习。为解决这些问题,我们提出了MedCo,一种基于LLM的图学习框架用于医学概念表示。MedCo首先通过结合从EHR中统计可靠的关联和类型受限的LLM提示构建全局知识图谱(KG),然后利用LLM将KG增强为带有文本属性的图,生成概念及其关系的语义信号。最后,MedCo联合训练了一个LoRA调优的LLaMA文本编码器和异构图神经网络(GNN),将文本语义和图结构融合为统一的概念嵌入。在MIMIC-III和MIMIC-IV上的大量实验表明,MedCo一致提升了预测性能,并作为标准EHR流程的有效概念编码器。

英文摘要:

In electronic health record (EHR) mining, learning high-quality representations of medical concepts (e.g., standardized diagnosis, medication, and procedure codes) is fundamental for downstream clinical prediction. However, ro bust concept representation learning is hindered by two key challenges: (i) clinically important cross-type dependencies (e.g., diagnosis medication and medication-procedure relations) are often missing or incomplete in existing ontology resources, limiting the ability to model complex EHR patterns; and (ii) rich clinical semantics are often missing from structured resources, and even when available as text, are difficult to integrate with KG structure for representation learning. To address these challenges, we present MedCo, an LLM empowered graph learning framework for medical concept representation. MedCo first builds a global knowledge graph (KG) over medical codes by combining statistically reliable associations mined from EHRs with type-constrained LLM prompting to infer semantic relations. It then utilizes LLMs to enrich the KG into a text-attributed graph by generating node descriptions and edge rationales, providing semantic signals for both concepts and their relationships. Finally, MedCo jointly trains a LoRA-tuned LLaMA text encoder with a heterogeneous GNN, fusing text semantics and graph structure into unified concept embeddings. Extensive experiments on MIMIC-III and MIMIC-IV show that MedCo consistently improves prediction performance and serves as an effective plug-in concept encoder for standard EHR pipelines.

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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