Title
An adaptive undersampling scheme of wavelet-encoded parallel MR imaging for more efficient MR data acquisition.
Abstract
Magnetic Resonance Imaging (MRI) offers noninvasive high resolution, high contrast cross-sectional anatomic images through the body. The data of the conventional MRI is collected in spatial frequency (Fourier) domain, also known as k-space. Because there is still a great need to improve temporal resolution of MRI, Compressed Sensing (CS) in MR imaging is proposed to exploit the sparsity of MR images showing great potential to reduce the scan time significantly, however, it poses its own unique problems. This paper revisits wavelet-encoded MR imaging which replaces phase encoding in conventional MRI data acquisition with wavelet encoding by applying wavelet-shaped spatially selective radiofrequency (RF) excitation, and keeps the readout direction as frequency encoding. The practicality of wavelet-encoded MRI by itself is limited due to the SNR penalties and poor time resolution compared to conventional Fourier-based MRI. To compensate for those disadvantages, this paper first introduces an undersampling scheme named significance map for sparse wavelet-encoded k-space to speed up data acquisition as well as allowing for various adaptive imaging strategies. The proposed adaptive wavelet-encoded undersampling scheme does not require prior knowledge of the subject to be scanned. Multiband (MB) parallel imaging is also incorporated with wavelet-encoded MRI by exciting multiple regions simultaneously for further reduction in scan time desirable for medical applications. The simulation and experimental results are presented showing the feasibility of the proposed approach in further reduction of the redundancy of the wavelet k-space data while maintaining relatively high quality.
Year
DOI
Venue
2016
10.1117/12.2217636
Proceedings of SPIE
Keywords
Field
DocType
Magnetic Resonance Imaging (MRI),wavelet-encoded MR imaging,adaptive wavelet encoding,significance map,sparsity,multiband selective excitation
Computer vision,k-space,Computer science,Data acquisition,Undersampling,Artificial intelligence,Real-time MRI,Temporal resolution,Compressed sensing,Spatial frequency,Wavelet
Conference
Volume
ISSN
Citations 
9784
0277-786X
0
PageRank 
References 
Authors
0.34
5
5
Name
Order
Citations
PageRank
Hua Xie100.34
John C. Bosshard200.34
Jason E. Hill312.09
Steven M Wright446.84
Sunanda Mitra525445.17