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Model‐based reconstruction of undersampled diffusion tensor k‐space data
Author(s) -
Welsh Christopher L.,
DiBella Edward V. R.,
Adluru Ganesh,
Hsu Edward W.
Publication year - 2013
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24486
Subject(s) - undersampling , diffusion mri , orientation (vector space) , compressed sensing , fractional anisotropy , tensor (intrinsic definition) , anisotropy , computer science , encoding (memory) , image resolution , algorithm , diffusion , artificial intelligence , computer vision , mathematics , physics , optics , magnetic resonance imaging , geometry , medicine , radiology , thermodynamics
The practical utility of diffusion tensor imaging, especially for 3D high‐resolution spin warp experiments of ex vivo specimens, has been hampered by long acquisition times. To accelerate the acquisition, a compressed sensing framework that uses a model‐based formulation to reconstruct diffusion tensor fields from undersampled k‐space data was presented and evaluated. Accuracies in brain specimen white matter fiber orientation, fractional anisotropy, and mean diffusivity mapping were compared with alternative methods achievable using the same scan time via reduced image resolution, fewer diffusion encoding directions, standard compressed sensing, or asymmetrical sampling reconstruction. The efficiency of the proposed approach was also compared with fully sampled cases across a range of the number of diffusion encoding directions. In general, the proposed approach was found to reduce the image blurring and noise and to provide more accurate fiber orientation, fractional anisotropy, and mean diffusivity measurements compared with the alternative methods. Moreover, depending on the degree of undersampling used and the diffusion tensor imaging parameter examined, the measurement accuracy of the proposed scheme was equivalent to fully sampled diffusion tensor imaging datasets that consist of 33–67% more encoding directions and require proportionally longer scan times. The findings show model‐based compressed sensing to be promising for improving the resolution, accuracy, or scan time of diffusion tensor imaging. Magn Reson Med 70:429–440, 2013. © 2012 Wiley Periodicals, Inc.