MCU-Net: A Multi-prior Collaborative Deep Unfolding Network with Gates-controlled Spatial Attention for Accelerated MR Image Reconstruction

TL;DR

MCU-Net introduces a multi-prior collaborative deep unfolding framework with a novel gates-controlled spatial attention mechanism, significantly improving MRI reconstruction speed and accuracy while reducing computational costs.

Contribution

The paper proposes MCU-Net, a novel multi-prior deep unfolding network with a gates-controlled spatial attention module, enhancing MRI reconstruction by effectively leveraging multiple priors and improving robustness.

Findings

Significant PSNR and SSIM improvements over state-of-the-art methods.

Reduced FLOPs while maintaining high reconstruction quality.

Effective multi-prior collaboration via confidence-guided modules.

Abstract

Deep unfolding networks (DUNs) have demonstrated significant potential in accelerating magnetic resonance imaging (MRI). However, they often encounter high computational costs and slow convergence rates. Besides, they struggle to fully exploit the complementarity when incorporating multiple priors. In this study, we propose a multi-prior collaborative DUN, termed MCU-Net, to address these limitations. Our method features a parallel structure consisting of different optimization-inspired subnetworks based on low-rank and sparsity, respectively. We design a gates-controlled spatial attention module (GSAM), evaluating the relative confidence (RC) and overall confidence (OC) maps for intermediate reconstructions produced by different subnetworks. RC allocates greater weights to the image regions where each subnetwork excels, enabling precise element-wise collaboration. We design correction modules to enhance the effectiveness in regions where both subnetworks exhibit limited performance, as indicated by low OC values, thereby obviating the need for additional branches. The gate units within GSAMs are designed to preserve necessary information across multiple iterations, improving the accuracy of the learned confidence maps and enhancing robustness against accumulated errors. Experimental results on multiple datasets show significant improvements on PSNR and SSIM results with relatively low FLOPs compared to cutting-edge methods. Additionally, the proposed strategy can be conveniently applied to various DUN structures to enhance their performance.