SGRNet: Spatially Guided Radiology Network for Structured Radiological Reporting of Head and Neck Cancer
Authors: Ayush Gupta, Vinkle Srivastav, Prateek Upadhya, Amit Gupta, Krithika Rangarajan, Nicolas Padoy
Organizations: University of Strasbourg, CNRS, INSERM, ICube, Strasbourg, France · IHU Strasbourg, France · Department of Data Science and AI, Wadhwani School of Data Science and AI (WSAI), Indian Institute of Technology (IIT) Madras, Chennai, India · All India Institute of Medical Sciences, New Delhi, India
Automated radiological report generation can alleviate clinical workloads and eliminate observer variability. However, standard free-text generation models pose hallucination risks in dense regions and fail under data scarcity. We address these challenges in Head and Neck Cancer (HNC) from contrast-enhanced CT (CECT) imaging. To enforce factual safety, we reformulate report generation as an anatomically grounded, multi-label, structured reporting task, predicting localized tumor involvement across a hierarchical clinical schema. To bridge the visual gap from missing metabolic imaging (e.g., PET), we introduce SGRNet (Spatially Guided Radiology Network), incorporating two low-cost spatial priors: automated organ segmentations and weakly supervised tumor localization maps modeled via 3D Gaussian heatmaps. These priors are dynamically integrated via spatial feature modulation to guide the network toward subtle tumor-induced structural alterations. Evaluated on a multi-centric dataset of 184 paired HNC CECT volumes and reports, on five clinically salient, densely packed anatomical subsites, SGRNet achieves a mean Average Precision (mAP) of 0.60, an 8.8 percentage-point absolute improvement over strong volume-only 3D baselines.
Figures & tables
Figure 1: Architecture of the SGRNet. The tumour heatmap and the organ segmentation stream modulate the CECT stream via spatial feature modulation, allowing the network to emphasise tumour-salient regions while preserving global anatomical context.
Model
Input
Tongue
Hypo- pharynx
Larynx Air
Strap + Thyroid
Carotid + IJV
Mean AP
DenseNet121
CECT Only
0.549
0.559
0.574
0.357
0.519
0.512
EfficientNet-B0
CECT Only
0.543
0.534
0.563
0.339
0.489
0.494
CT-FM [ 25 ]
CECT Only
0.419
0.576
0.612
0.256
0.579
0.488
Simple Overlap Baseline
Org+Tum-Overlap
0.531
0.690
0.724
0.401
0.523
0.574
DenseNet121
Org-Add
0.504
0.725
0.699
0.314
0.627
0.574
DenseNet121
Org-Modul
0.494
0.674
0.756
0.447
0.601
0.594
Table 1: Average Precision (AP) for baseline CECT models, the non-learned overlap baseline, prior-blending ablations, and the final SGRNet variants. (IJV: Internal Jugular Vein. Notable values highlighted in bold; final SGRNet rows shown in bold).
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
Figure A.1: Visual comparison of imaging modalities. (A) PET/CT highlights metabolically active tumour regions via radiotracer uptake. (B) PET/MRI provides high soft-tissue contrast with PET-guided localisation. (C) CECT lacks metabolic tracers, resulting in more subtle tumour boundaries and motivating the need for automated interpretability methods.
General Information
Additional Structures
Patient ID
Airway compromise
Primary tumour location
Endotracheal tube in-situ
Tumour size
Thyroid cartilage
Cricoid cartilage
Oral Cavity
Esophagus
Lip
Prevertebral space
Appendix
Table A.1: Structured reporting template used for head and neck cancer CT examinations.
Parameter
Value
Unit
Total scans
184
–
Average voxel spacing
1×1×1
mm 3
Average resolution
512×510
pixels
Average number of slices
288
slices
Average mean HU
−763 (Std. 576)
HU
HU range
[−1732,3444]
HU
Appendix
Table A.2: Summary of dataset-level imaging characteristics.
ID
Structure
0
Background
1
Larynx air
2
Thyroid cartilage
3
Cricoid cartilage
4
Hyoid bone
5
Tongue
Appendix
Table A.3: Segmented organs and corresponding label identifiers.
Figure A.2: Qualitative results from the anatomical organ segmentation model. Panels (A)–(C) illustrate representative outputs from three different patients showing the predicted masks for the 21 anatomical structures.
Figure A.3: Tumour segmentation results from an nnU-Net model trained exclusively on CT images from the public PET/CT dataset. Panels (A)–(C) show representative examples.
Figure A.4: Tumour segmentation results from the nnU-Net model pre-trained on the public PET/CT dataset and subsequently fine-tuned using the manually curated cuboid regions. Panels (A)–(C) show representative examples.
Recent advances in radiology report generation (RRG) have been driven by large paired image-text datasets; however, progress in neuro-oncology has been limited due to a lack of open paired image-report datasets. Here, we introduce BTReport, an open-source framework for brain tumor RRG that constructs natural language radiology reports using deterministically extracted imaging features. Unlike existing approaches that rely on large general-purpose or fine-tuned vision-language models for both image interpretation and report composition, BTReport performs deterministic feature extraction for image analysis and uses large language models only for syntactic structuring and narrative formatting. By separating RRG into a deterministic feature extraction step and a report generation step, the generated reports are completely interpretable and less prone to hallucinations. We show that the features used for report generation are predictive of key clinical outcomes, including survival and IDH mutation status, and reports generated by BTReport are more closely aligned with reference clinical reports than existing baselines for RRG. Finally, we introduce BTReport-BraTS, a companion dataset that augments BraTS imaging with synthetically generated radiology reports produced with BTReport. Code for this project can be found at https://github.com/KurtLabUW/BTReport.
Juampablo E. Heras Rivera, Dickson T. Chen, Tianyi Ren +4
University of Washington · University of Washington School of Medicine · Microsoft Health AI +1
Vision--language models (VLMs) for radiology report generation (RRG) can produce long-form chest CT reports from volumetric scans and show strong potential to improve radiology workflow efficiency and consistency. However, existing methods face two key limitations: (i) training supervision is often coarse, aligning a whole CT volume with a full free-text report without explicit alignment for fine-grained attributes or pathology locations; and (ii) evaluation is typically holistic (lexical overlap, entity matching, or LLM-as-a-judge scores) and not diagnostic for spatial grounding. We propose Discriminative Cue-Prompting with Prompt Dropout (DCP-PD), a plug-and-play framework that distills fine-grained cues from free-text reports and uses them to guide report generation while mitigating shortcut reliance via prompt dropout. DCP-PD achieves state-of-the-art performance on CT-RATE, improving macro F1 from =0.501 to 0.603 (20% relative), and substantially boosts out-of-distribution performance on Rad-ChestCT from F1 =0.266 to 0.503 (89% relative). Finally, we introduce a hierarchical, location-aware question-set protocol (presence → laterality → lobe) to directly assess pathology-location grounding, showing that fine-grained spatial localization remains challenging even for models that score highly on current benchmarks.
Chenyu Wang, Weicheng Dai, Han Liu +2
Boston University, Boston, MA, USA · Siemens Healthineers, Princeton, NJ, USA
Computed Tomography Report Generation (CTRG) aims to automate the clinical radiology reporting process, thereby reducing the workload of report writing and facilitating patient care. While deep learning approaches have achieved remarkable advances in X-ray report generation, their effectiveness may be limited in CTRG due to larger data volumes of CT images and more intricate details required to describe them. This work introduces a novel two-stage (structure- and report-learning) framework tailored for CTRG featuring effective structure-wise image-text contrasting. In the first stage, a set of learnable structure-specific visual queries observe corresponding structures in a CT image. The resulting observation tokens are contrasted with structure-specific textual features extracted from the accompanying radiology report with a structure-wise image-text contrastive loss. In addition, text-text similarity-based soft pseudo targets are proposed to mitigate the impact of false negatives, i.e., semantically identical image structures and texts from non-paired images and reports. Thus, the model learns structure-level semantic correspondences between CT images and reports. Further, a dynamic, diversity-enhanced negative queue is proposed to guide the network in learning to discriminate various abnormalities. In the second stage, the visual structure queries are frozen and used to select the critical image patch embeddings depicting each anatomical structure, minimizing distractions from irrelevant areas while reducing memory consumption. Also, a text decoder is added and trained for report generation.Our extensive experiments on two public datasets demonstrate that our framework establishes new state-of-the-art performance for CTRG in clinical efficiency, and its components are effective.
Hong Liu, Dong Wei, Qiong Peng +4
National Institute for Data Science in Health and Medicine, Xiamen University · Jarvis Research Center, Tencent YouTu Lab, Shenzhen, China · School of Informatics, Xiamen University, Xiamen, China +1