A Deep Cascade of Convolutional Neural Networks for Dynamic MR Image Reconstruction
This addresses the problem of slow MR acquisition for medical imaging, offering a faster and more accurate method, though it is incremental as it builds on existing deep learning approaches.
The paper tackles dynamic cardiac MR image reconstruction from undersampled data using a deep cascade of CNNs, achieving up to 11-fold undersampling with improved reconstruction error and speed, enabling real-time applications with reconstruction times as low as 23ms per frame.
Inspired by recent advances in deep learning, we propose a framework for reconstructing dynamic sequences of 2D cardiac magnetic resonance (MR) images from undersampled data using a deep cascade of convolutional neural networks (CNNs) to accelerate the data acquisition process. In particular, we address the case where data is acquired using aggressive Cartesian undersampling. Firstly, we show that when each 2D image frame is reconstructed independently, the proposed method outperforms state-of-the-art 2D compressed sensing approaches such as dictionary learning-based MR image reconstruction, in terms of reconstruction error and reconstruction speed. Secondly, when reconstructing the frames of the sequences jointly, we demonstrate that CNNs can learn spatio-temporal correlations efficiently by combining convolution and data sharing approaches. We show that the proposed method consistently outperforms state-of-the-art methods and is capable of preserving anatomical structure more faithfully up to 11-fold undersampling. Moreover, reconstruction is very fast: each complete dynamic sequence can be reconstructed in less than 10s and, for the 2D case, each image frame can be reconstructed in 23ms, enabling real-time applications.