HEMP: Hierarchical Entity-aligned Memory Prompting for CT Report Generation

Tong Xu, Yiming Qian, Zhe Shan, Xia Xie


Abstract
Automated CT report generation remains challenging because it requires both fine-grained grounding of pathological entities in multi-view volumetric evidence and clinically coherent language that reflects diagnostic priors from historical cases. Existing methods often rely on noisy cross-modal alignment or underutilize retrieved report knowledge during decoding. We propose HEMP, which is a Hierarchical Entity-aligned Memory Prompting framework for LLM-based CT report generation. HEMP first performs two-stage entity-visual alignment where graph-constrained entity-conditioned attention retrieves initial evidence and an optimal transport refinement enforces principled coupling between entity nodes and visual tokens under marginal constraints. To inject case-conditioned linguistic priors, we design a Conditional Dual-Hopfield Memory module that retrieves case-conditioned report priors and integrates them through both implicit feature-level fusion into entity representations and explicit memory tokens appended to the prompt. Finally, we enforce clinical consistency via hierarchical severity supervision at the entity, region, and sign-group levels. Comprehensive Experiments demonstrate that our method outperforms previous methods and achieves SoTA performance.
Anthology ID:
2026.emnlp-main.1545
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
35250–35260
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1545/
DOI:
Bibkey:
Cite (ACL):
Tong Xu, Yiming Qian, Zhe Shan, and Xia Xie. 2026. HEMP: Hierarchical Entity-aligned Memory Prompting for CT Report Generation. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 35250–35260, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
HEMP: Hierarchical Entity-aligned Memory Prompting for CT Report Generation (Xu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1545.pdf