DMFF-Net: Densely Macroscopic Feature Fusion Network for Fast Magnetic Resonance Image Reconstruction

Abstract

The task of fast magnetic resonance (MR) image reconstruction is to reconstruct high-quality MR images from undersampled images. Most of the existing methods are based on U-Net, and these methods mainly adopt several simple connections within the network, which we call microscopic design ideas. However, these considerations cannot make full use of the feature information inside the network, which leads to low reconstruction quality. To solve this problem, we rethought the feature utilization method of the encoder and decoder network from a macroscopic point of view and propose a densely macroscopic feature fusion network for fast magnetic resonance image reconstruction. Our network uses three stages to reconstruct high-quality MR images from undersampled images from coarse to fine. We propose an inter-stage feature compensation structure (IFCS) which makes full use of the feature information of different stages and fuses the features of different encoders and decoders. This structure uses a connection method between sub-networks similar to dense form to fuse encoding and decoding features, which is called densely macroscopic feature fusion. A cross network attention block (CNAB) is also proposed to further improve the reconstruction performance. Experiments show that the quality of undersampled MR images is greatly improved, and the detailed information of MR images is enriched to a large extent. Our reconstruction network is lighter than many previous methods, but it achieves better performance. The performance of our method is about 10% higher than that of the original method, and about 3% higher than that of most existing methods. Compared with the nearest optimal algorithms, the performance of our method is improved by about 0.01–0.45%, and our computational complexity is only 1/14 of these algorithms.