Joint alignment and reconstruction of multislice dynamic MRI using variational manifold learning

TL;DR

This paper introduces an unsupervised deep learning method that jointly aligns and reconstructs multislice dynamic MRI data, improving upon existing methods by capturing inter-slice redundancies and motion variations without manual intervention.

Contribution

It proposes a novel variational deep manifold learning approach for simultaneous alignment and reconstruction of multislice dynamic MRI data, addressing limitations of independent slice recovery.

Findings

Enhanced image alignment and reconstruction quality.

Reduced need for manual post-processing.

Effective modeling of inter-slice redundancies.

Abstract

Free-breathing cardiac MRI schemes are emerging as competitive alternatives to breath-held cine MRI protocols, enabling applicability to pediatric and other population groups that cannot hold their breath. Because the data from the slices are acquired sequentially, the cardiac/respiratory motion patterns may be different for each slice; current free-breathing approaches perform independent recovery of each slice. In addition to not being able to exploit the inter-slice redundancies, manual intervention or sophisticated post-processing methods are needed to align the images post-recovery for quantification. To overcome these challenges, we propose an unsupervised variational deep manifold learning scheme for the joint alignment and reconstruction of multislice dynamic MRI. The proposed scheme jointly learns the parameters of the deep network as well as the latent vectors for each slice, which capture the motion-induced dynamic variations, from the k-t space data of the specific subject. The variational framework minimizes the non-uniqueness in the representation, thus offering improved alignment and reconstructions.