Logo image
Fast iterative algorithm for the reconstruction of multishot non-cartesian diffusion data
Journal article   Peer reviewed

Fast iterative algorithm for the reconstruction of multishot non-cartesian diffusion data

Merry Mani, Mathews Jacob, Vincent Magnotta and Jianhui Zhong
Magnetic resonance in medicine, Vol.74(4), pp.1086-1094
10/2015
DOI: 10.1002/mrm.25486
PMID: 25323847

View Online

Abstract

To accelerate the motion-compensated iterative reconstruction of multishot non-Cartesian diffusion data. The motion-compensated recovery of multishot non-Cartesian diffusion data is often performed using a modified iterative sensitivity-encoded algorithm. Specifically, the encoding matrix is replaced with a combination of nonuniform Fourier transforms and composite sensitivity functions, which account for the motion-induced phase errors. The main challenge with this scheme is the significantly increased computational complexity, which is directly related to the total number of composite sensitivity functions (number of shots × number of coils). The dimensionality of the composite sensitivity functions and hence the number of Fourier transforms within each iteration is reduced using a principal component analysis-based scheme. Using a Toeplitz-based conjugate gradient approach in combination with an augmented Lagrangian optimization scheme, a fast algorithm is proposed for the sparse recovery of diffusion data. The proposed simplifications considerably reduce the computation time, especially in the recovery of diffusion data from under-sampled reconstructions using sparse optimization. By choosing appropriate number of basis functions to approximate the composite sensitivities, faster reconstruction (close to 9 times) with effective motion compensation is achieved. The proposed enhancements can offer fast motion-compensated reconstruction of multishot diffusion data for arbitrary k-space trajectories.
Reproducibility of Results Algorithms Brain - anatomy & histology Humans Adult Image Processing, Computer-Assisted - methods Diffusion Magnetic Resonance Imaging - methods Principal Component Analysis

Details

Metrics

Logo image