Accelerating Dynamic Spiral MRI by Algebraic Reconstruction From Undersampled Space
Taehoon Shin
Nielsen, J-F.
Nayak, K.S.
Southern California Univ., Los Angeles;
This paper appears in: Medical Imaging, IEEE Transactions on
Publication Date: July 2007
Volume: 26,
Issue: 7
On page(s): 917-924
Location: Davis, CA, USA,
ISSN: 0278-0062
INSPEC Accession Number: 9596761
Digital Object Identifier: 10.1109/TMI.2007.895450
Current Version Published: 2007-07-02
Abstract
The temporal resolution of dynamic magnetic resonance imaging (MRI) can be increased by sampling a fraction of k-space in an interleaved fashion, which introduces spatial and temporal aliasing. We describe algebraically and graphically the aliasing process caused by dynamic undersampled spiral imaging within 3D xy f space (the Fourier transform of kxkyt space) and formulate the unaliasing problem as a set of independent linear inversions. Since each linear system is numerically underdetermined, the use of prior knowledge in the form of bounded support regions is proposed. To overcome the excessive memory requirements for handling large matrices, a fast implementation of the conjugate gradient (CG) method is used. Numerical simulation and in vivo experiments using spiral twofold undersampling demonstrate reduced motion artifacts and the improved depiction of fine cardiac structures. The achieved reduction of motion artifacts and motion blur is comparable to simple filtering, which is computationally more efficient, while the proposed algebraic framework offers greater flexibility to incorporate additional algebraic acceleration techniques and to handle arbitrary sampling schemes.
Index
Terms
Available to subscribers and IEEE members.
References
Available to subscribers and IEEE members.
Citing Documents
Available to subscribers and IEEE members.
Cart
