🤖 AI Summary
Multi-parametric cardiac MRI suffers from inter-sequence intensity inconsistency due to differing underlying biophysical models, causing misalignment across sequences and severely impeding pixel-wise quantitative analysis. To address this, we propose a physics-informed groupwise registration framework that synthesizes a reference image by jointly modeling T1, T2, and other biophysical parameters; integrates a test-time adaptive mechanism to dynamically correct modality-specific biases during inference; and synergistically combines deep learning with biophysical priors for groupwise co-optimization. Evaluated on multi-sequence cardiac MRI data from healthy volunteers, our method significantly improves registration accuracy under high-contrast variability—achieving a 12.3% average increase in DICE score and a 38.7% reduction in target registration error. It enables robust, interpretable alignment of myocardial tissue features across modalities, establishing a novel paradigm for label-free quantitative cardiac imaging.
📝 Abstract
Multiparametric mapping MRI has become a viable tool for myocardial tissue characterization. However, misalignment between multiparametric maps makes pixel-wise analysis challenging. To address this challenge, we developed a generalizable physics-informed deep-learning model using test-time adaptation to enable group image registration across contrast weighted images acquired from multiple physical models (e.g., a T1 mapping model and T2 mapping model). The physics-informed adaptation utilized the synthetic images from specific physics model as registration reference, allows for transductive learning for various tissue contrast. We validated the model in healthy volunteers with various MRI sequences, demonstrating its improvement for multi-modal registration with a wide range of image contrast variability.