GraphRAG-Rad: Concept-Aware Radiology Report Generation via Latent Visual-Semantic Retrieval

Faezeh Safari, Hang Dong, Zeyu Fu, Aline Villavicencio


Abstract
Radiology report generation involves translating visual signals from pixels into precise clinical language. Existing encoder-decoder models often suffer from hallucinations, generating plausible but incorrect medical findings. We propose GraphRAG-Rad, a novel architecture that integrates biomedical knowledge through a novel Latent Visual-Semantic Retrieval (VSR). Unlike traditional Retrieval-Augmented Generation (RAG) methods that rely on textual queries, our approach aligns visual embeddings with the latent space of the Knowledge Graph, PrimeKG. The retrieved sub-graph guides the Visual Encoder and the Multi-Hop Reasoning Module. The reasoning module simulates clinical deduction paths (Ground-Glass Opacity → Viral Pneumonia → COVID-19) before it combines the information with visual features in a Graph-Gated Cross-Modal Decoder. Experiments on the COV-CTR dataset demonstrate that GraphRAG-Rad achieves competitive performance with strong results across multiple metrics. Furthermore, ablation studies show that integrating latent retrieval and reasoning improves performance significantly compared to a visual-only baseline. Qualitative analysis further reveals interpretable attention maps. These maps explicitly link visual regions to symbolic medical concepts, effectively bridging the modality gap between vision and language.
Anthology ID:
2026.eacl-srw.34
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 4: Student Research Workshop)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Selene Baez Santamaria, Sai Ashish Somayajula, Atsuki Yamaguchi
Venue:
EACL
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Publisher:
Association for Computational Linguistics
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Pages:
464–475
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URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-srw.34/
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Cite (ACL):
Faezeh Safari, Hang Dong, Zeyu Fu, and Aline Villavicencio. 2026. GraphRAG-Rad: Concept-Aware Radiology Report Generation via Latent Visual-Semantic Retrieval. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 4: Student Research Workshop), pages 464–475, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
GraphRAG-Rad: Concept-Aware Radiology Report Generation via Latent Visual-Semantic Retrieval (Safari et al., EACL 2026)
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-srw.34.pdf