Multimodal Dual-Path Decoding for Medical Report Generation
Paper · 2026 · Jinghan Sun, Dong Wei, Zhihong Zhu et al.
Summary
This Findings of ACL 2026 paper automatically writes chest X-ray reports. Its PDF title reads "…Large-Model Decoding for Radiology Report Generation". The authors argue that vision-language models see the image well but lack medical background knowledge. Text-only LLMs have the opposite profile. To combine them, they fine-tune two models separately. Qwen2-VL-7B reads the X-rays. Qwen2-7B receives a prompt listing labels from a multi-label disease classifier: positive, negative, uncertain or not mentioned. Both models produce the same structured output: disease categories, Impression and Findings. At inference, their predictions are merged token by token while decoding, rather than by combining finished outputs. Experiments on MIMIC-CXR and IU-Xray show better clinical efficacy than prior methods. Ablations confirm that the fused system beats either model alone in precision and F1. The work matters because it shows how to combine an image-grounded model with a knowledge-rich language model to produce reports that are more clinically correct, not just more fluent.
Key points
- Backbones: Qwen2-VL-7B (LVLM) and Qwen2-7B (LLM). They are trained separately and fused through token-level ensembling at decoding time. The method requires both models to share an aligned vocabulary.
- MIMIC-CXR ablation, clinical efficacy: The fused model reaches precision 0.591 and F1 0.527. LVLM-only scores 0.535 and 0.497; LLM-only scores 0.483 and 0.485. Recall is the exception: LLM-only stays highest (0.517 vs 0.476 for the fused model).
- MIMIC-CXR ablation, text-similarity metrics: BLEU-1 rises to 0.280 (vs 0.246 and 0.238) and BLEU-4 to 0.070. ROUGE (0.286) is roughly equal to LVLM-only (0.288).
- IU-Xray: The authors report a clinical F1 improvement of 0.028 over competing methods.
- Reported limitations: Results depend on the quality of the two backbones, and the vocabulary-alignment requirement narrows the choice of model pairs. MIMIC-CXR (~0.22M samples) is noted as small compared with general captioning datasets.
Institutions
Fields, topics and concepts
📚 Shelves 5The field of science this work belongs to (OpenAlex fields).Computer Science · 16,667 worksArtificial Intelligence · 16,194 worksComputer Vision and Pattern Recognition · 2,869 worksMedicine · 241 worksHealth Informatics · 184 works
🧭 Topics 1Research subjects and languages the work is about.Vision & language · 657 works
Cite
Cite as Jinghan Sun, Dong Wei, Zhihong Zhu, Yuyang Xue, Steven McDonagh and Xian Wu. 2026. Multimodal Dual-Path Decoding for Medical Report Generation. Findings of the Association for Computational Linguistics: ACL 2026.
@inproceedings{sun2026multimodal,
title = {{Multimodal Dual-Path Decoding for Medical Report Generation}},
author = {Jinghan Sun, Dong Wei, Zhihong Zhu, Yuyang Xue, Steven McDonagh and Xian Wu},
booktitle = {Findings of the Association for Computational Linguistics: ACL 2026},
year = {2026},
doi = {10.18653/v1/2026.findings-acl.1997},
url = {https://doi.org/10.18653/v1/2026.findings-acl.1997}
}References
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