Deep Unrolled Meta-Learning for Multi-Coil and Multi-Modality MRI with Adaptive Optimization
Merham Fouladvand, Peuroly Batra
TL;DR
This work addresses accelerated MRI by jointly reconstructing multi-coil data and synthesizing missing modalities under undersampling. It introduces a deep unrolled framework that solves phi_eta(x) = f(x) + r_eta(x) via an adaptive forward-backward optimization with extrapolation, featuring a learnable fusion operator and complex-valued processing. The approach offers convergence guarantees and meta-learning capabilities, demonstrating superior PSNR and SSIM on fastMRI and BraTS-like tasks under aggressive undersampling and domain shifts. Overall, the method provides a scalable, generalizable solution for clinical MRI that reduces scan time while enabling robust cross-modality synthesis.
Abstract
We propose a unified deep meta-learning framework for accelerated magnetic resonance imaging (MRI) that jointly addresses multi-coil reconstruction and cross-modality synthesis. Motivated by the limitations of conventional methods in handling undersampled data and missing modalities, our approach unrolls a provably convergent optimization algorithm into a structured neural network architecture. Each phase of the network mimics a step of an adaptive forward-backward scheme with extrapolation, enabling the model to incorporate both data fidelity and nonconvex regularization in a principled manner. To enhance generalization across different acquisition settings, we integrate meta-learning, which enables the model to rapidly adapt to unseen sampling patterns and modality combinations using task-specific meta-knowledge. The proposed method is evaluated on the open source datasets, showing significant improvements in PSNR and SSIM over conventional supervised learning, especially under aggressive undersampling and domain shifts. Our results demonstrate the synergy of unrolled optimization, task-aware meta-learning, and modality fusion, offering a scalable and generalizable solution for real-world clinical MRI reconstruction.
