Abstract
Magnetic resonance diffusion tensor imaging (DTI) provides a powerful
tool for mapping neural histoarchitecture in vivo. However, DTI
can only resolve a single fiber orientation within each imaging
voxel due to the constraints of the tensor model. For example, DTI
cannot resolve fibers crossing, bending, or twisting within an individual
voxel. Intravoxel fiber crossing can be resolved using q-space diffusion
imaging, but q-space imaging requires large pulsed field gradients
and time-intensive sampling. It is also possible to resolve intravoxel
fiber crossing using mixture model decomposition of the high angular
resolution diffusion imaging (HARDI) signal, but mixture modeling
requires a model of the underlying diffusion process.Recently, it
has been shown that the HARDI signal can be reconstructed model-independently
using a spherical tomographic inversion called the Funk-Radon transform,
also known as the spherical Radon transform. The resulting imaging
method, termed q-ball imaging, can resolve multiple intravoxel fiber
orientations and does not require any assumptions on the diffusion
process such as Gaussianity or multi-Gaussianity. The present paper
reviews the theory of q-ball imaging and describes a simple linear
matrix formulation for the q-ball reconstruction based on spherical
radial basis function interpolation. Open aspects of the q-ball
reconstruction algorithm are discussed. Magn Reson Med 52:1358-1372,
2004. © 2004 Wiley-Liss, Inc.
Description
Diffusion Tensor Imaging (DTI)
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