ReconResNet: Regularised residual learning for MR image reconstruction of Undersampled Cartesian and Radial data. (April 2022)

• Record Type: Journal Article
• Authors: Chatterjee, Soumick; Breitkopf, Mario; Sarasaen, Chompunuch; Yassin, Hadya; Rose, Georg; Nürnberger, Andreas; Speck, Oliver
• Is Part Of: Computers in biology and medicine. Volume 143(2022)
• Publication Date: 2022-04
• Subjects: MRI -- MR Image reconstruction -- Undersampled MRI -- Undersampled MR Reconstruction -- Radial sampling reconstruction -- Deep learning; Medicine -- Data processing -- Periodicals; Biology -- Data processing -- Periodicals; 610.285
• DOI: 10.1016/j.compbiomed.2022.105321
• Languages: English
• ISSNs: 0010-4825

Abstract

Abstract: MRI is an inherently slow process, which leads to long scan time for high-resolution imaging. The speed of acquisition can be increased by ignoring parts of the data (undersampling). Consequently, this leads to the degradation of image quality, such as loss of resolution or introduction of image artefacts. This work aims to reconstruct highly undersampled Cartesian or radial MR acquisitions, with better resolution and with less to no artefact compared to conventional techniques like compressed sensing. In recent times, deep learning has emerged as a very important area of research and has shown immense potential in solving inverse problems, e.g. MR image reconstruction. In this paper, a deep learning based MR image reconstruction framework is proposed, which includes a modified regularised version of ResNet as the network backbone to remove artefacts from the undersampled image, followed by data consistency steps that fusions the network output with the data already available from undersampled k-space in order to further improve reconstruction quality. The performance of this framework for various undersampling patterns has also been tested, and it has been observed that the framework is robust to deal with various sampling patterns, even when mixed together while training, and results in very high quality reconstruction, in terms of high SSIM (highest being 0.990 ± 0.006 for acceleration factor of 3.5), while being compared with the fully sampled reconstruction. It has been shown that the proposed framework can successfully reconstruct even for an acceleration factor of 20 for Cartesian (0.968 ± 0.005) and 17 for radially (0.962 ± 0.012) sampled data. Furthermore, it has been shown that the framework preserves brain pathology during reconstruction while being trained on healthy subjects. Highlights: Undersampled Cartesian and Radial MRI Reconstruction using the proposed ReconResNet. Evaluated using two healthy and two pathological datasets. Achived the best SSIM of 0.990 ± 0.006 for an acceleration factor of 3.5. Reconstructed successfully up to an acceleration factor of 20 Cartesian and 17 Radial.