Multimodal MRI Report Findings Supervised Brain Lesion Segmentation with Substructures
arXiv:2602.20994v1 Announce Type: cross Abstract: Report-supervised (RSuper) learning seeks to alleviate the need for dense tumor voxel labels with constraints derived from radiology reports (e.g., volumes, counts, sizes, locations). In MRI studies of brain tumors, however, we often involve multi-parametric scans and substructures. Here, fine-grained modality/parameter-wise reports are usually provided along with global findings and are correlated with different substructures. Moreover, the reports often describe only the largest lesion and provide qualitative or uncertain cues (``mild,'' ``possible''). Classical RSuper losses (e.g., sum volume consistency) can over-constrain or hallucinate unreported findings under such incompleteness, and are unable to utilize these hierarchical findings or exploit the priors of varied lesion types in a merged dataset. We explicitly parse the global quantitative and modality-wise qualitative findings and introduce a unified, one-sided, uncertainty-a
arXiv:2602.20994v1 Announce Type: cross Abstract: Report-supervised (RSuper) learning seeks to alleviate the need for dense tumor voxel labels with constraints derived from radiology reports (e.g., volumes, counts, sizes, locations). In MRI studies of brain tumors, however, we often involve multi-parametric scans and substructures. Here, fine-grained modality/parameter-wise reports are usually provided along with global findings and are correlated with different substructures. Moreover, the reports often describe only the largest lesion and provide qualitative or uncertain cues (``mild,'' ``possible''). Classical RSuper losses (e.g., sum volume consistency) can over-constrain or hallucinate unreported findings under such incompleteness, and are unable to utilize these hierarchical findings or exploit the priors of varied lesion types in a merged dataset. We explicitly parse the global quantitative and modality-wise qualitative findings and introduce a unified, one-sided, uncertainty-aware formulation (MS-RSuper) that: (i) aligns modality-specific qualitative cues (e.g., T1c enhancement, FLAIR edema) with their corresponding substructures using existence and absence losses; (ii) enforces one-sided lower-bounds for partial quantitative cues (e.g., largest lesion size, minimal multiplicity); and (iii) adds extra- vs. intra-axial anatomical priors to respect cohort differences. Certainty tokens scale penalties; missing cues are down-weighted. On 1238 report-labeled BraTS-MET/MEN scans, our MS-RSuper largely outperforms both a sparsely-supervised baseline and a naive RSuper method.
Executive Summary
This article presents a novel approach to supervised brain lesion segmentation with substructures in multimodal MRI reports. The proposed method, MS-RSuper, addresses the limitations of classical report-supervised learning by incorporating modality-specific qualitative cues, one-sided lower-bounds for partial quantitative cues, and anatomical priors. The method outperforms a sparsely-supervised baseline and a naive RSuper method on a dataset of 1238 report-labeled scans. The results demonstrate the potential of MS-RSuper for improved brain tumor segmentation and substructure identification.
Key Points
- ▸ MS-RSuper addresses the limitations of classical report-supervised learning
- ▸ The method incorporates modality-specific qualitative cues and one-sided lower-bounds for partial quantitative cues
- ▸ Anatomical priors are added to respect cohort differences
Merits
Improved Performance
MS-RSuper outperforms both a sparsely-supervised baseline and a naive RSuper method on a dataset of 1238 report-labeled scans
Flexibility and Adaptability
MS-RSuper can handle incompleteness in radiology reports and utilize hierarchical findings
Uncertainty-Aware Formulation
Certainty tokens scale penalties and missing cues are down-weighted
Demerits
Complexity
The proposed method may be more complex and challenging to implement compared to classical report-supervised learning
Limited Generalizability
The method may not generalize well to other datasets or applications
Expert Commentary
The article presents a novel and intriguing approach to supervised brain lesion segmentation with substructures in multimodal MRI reports. The proposed method, MS-RSuper, addresses the limitations of classical report-supervised learning by incorporating modality-specific qualitative cues, one-sided lower-bounds for partial quantitative cues, and anatomical priors. The results are promising, and the method shows potential for improved brain tumor segmentation and substructure identification. However, the complexity and limited generalizability of the method may be concerns for implementation and adoption. Further research is needed to evaluate the robustness and scalability of MS-RSuper.
Recommendations
- ✓ Further evaluation of the method on larger and more diverse datasets
- ✓ Investigation of the method's performance on other types of medical imaging data