Quantitative assessment of diffusional kurtosis anisotropy.
Diffusional kurtosis imaging (DKI) measures the diffusion and kurtosis tensors to quantify restricted, non-Gaussian diffusion that occurs in biological tissue. By estimating the kurtosis tensor, DKI accounts for higher order diffusion dynamics, when compared with diffusion tensor imaging (DTI), and consequently can describe more complex diffusion profiles. Here, we compare several measures of diffusional anisotropy which incorporate information from the kurtosis tensor, including kurtosis fractional anisotropy (KFA) and generalized fractional anisotropy (GFA), with the diffusion tensor-derived fractional anisotropy (FA). KFA and GFA demonstrate a net enhancement relative to FA when multiple white matter fiber bundle orientations are present in both simulated and human data. In addition, KFA shows net enhancement in deep brain structures, such as the thalamus and the lenticular nucleus, where FA indicates low anisotropy. Thus, KFA and GFA provide additional information relative to FA with regard to diffusional anisotropy, and may be particularly advantageous for the assessment of diffusion in complex tissue environments.
Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
G Russell
GR
Glenn
Joseph A
JA
Helpern
Ali
A
Tabesh
Jens H
JH
Jensen
D000328:Adult; D000465:Algorithms; D016880:Anisotropy; D066264:Datasets as Topic; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D056324:Diffusion Tensor Imaging / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D016011:Normal Distribution; D066127:White Matter / Q000033:anatomy & histology*
DKI; FA; GFA; KFA; anisotropy; diffusion; kurtosis; non-Gaussian