CrossPan: A Comprehensive Benchmark for Cross-Sequence Pancreas MRI Segmentation and Generalization
Summary
CrossPan is a new multi-institutional benchmark designed to evaluate the generalization capabilities of deep learning models for pancreas MRI segmentation across different MRI sequences. The benchmark includes 1,386 3D scans from eight centers, covering T1-weighted, T2-weighted, and Out-of-Phase sequences. Experiments using CrossPan reveal that cross-sequence domain shifts pose a significantly greater challenge than cross-center variability; models achieving Dice scores above 0.85 in-domain drop to below 0.02 when transferred across sequences. Furthermore, traditional domain generalization methods offer minimal improvement, while foundation models like MedSAM2 show moderate zero-shot performance due to contrast-invariant shape priors. Semi-supervised learning is found to be effective only under stable intensity distributions, becoming unstable with high intra-organ variability. These findings highlight cross-sequence generalization as the primary obstacle to deploying pancreas MRI segmentation models clinically.
Key takeaway
For AI Scientists developing medical image segmentation models, you should prioritize addressing cross-sequence generalization over architectural improvements or increasing center diversity. Your models must maintain performance across diverse MRI sequences, as current methods fail catastrophically. Consider integrating foundation models that leverage contrast-invariant shape priors to improve robustness in zero-shot scenarios, and be wary of semi-supervised learning in highly variable sequences.
Key insights
Cross-sequence domain shift is the primary barrier to robust pancreas MRI segmentation.
Principles
- Cross-sequence shifts are more severe than cross-center variability.
- Foundation models use contrast-invariant shape priors for generalization.
In practice
- Prioritize cross-sequence generalization in model development.
- Evaluate foundation models for zero-shot segmentation tasks.
Topics
- Pancreas Segmentation
- Cross-Sequence Generalization
- MRI Domain Shift
- Deep Learning Models
- MedSAM2
Best for: AI Scientist, Research Scientist, Computer Vision Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.CV updates on arXiv.org.