1. Definitions: a. Diffusion Tensor Imaging (DTI) refers to the acquisition and reconstruction of MR images with diffusion-encoding gradients applied in a minimum of 6 non-collinear directions, followed by voxel-wise calculation of the tensor representation of a 3D Gaussian model of the diffusion profile and subsequent mapping of any number of tensor parameters. Most commonly these would includ...

We consider the problem of segmenting fiber bundles in diffusion tensor images. We cast this problem as a manifold clustering problem in which different fiber bundles correspond to different submanifolds of the space of diffusion tensors. We first learn a local representation of the diffusion tensor data using a generalization of the locally linear embedding (LLE) algorithm from Euclidean to di...

Diffusion tensor imaging is a sensitive way to reflect axonal necrosis and degeneration, glial cell regeneration and demyelination following spinal cord injury, and to display microstructure changes in the spinal cord in vivo. Diffusion tensor imaging technology is a sensitive method to diagnose spinal cord injury; fiber tractography visualizes the white matter fibers, and directly displays the...

We investigate new approaches to quantifying the white matter connectivity in the brain using Diffusion Tensor Magnetic Resonance Imaging data. Our first approach finds a steady-state concentration/heat distribution using the three-dimensional tensor field as diffusion/conductivity tensors. Our second approach casts the problem in a Riemannian framework, deriving from each tensor a local warpin...

BACKGROUND Diffusion tensor imaging exploits preferential diffusional motion of water molecules residing within tissue compartments for assessment of tissue structural anisotropy. However, instrumentation and post-processing errors play an important role in determination of diffusion tensor elements. In the study, several experimental factors affecting accuracy of diffusion tensor determination...

OBJECTIVES To investigate the extent of tissue damage in a region of normal appearing corpus callosum (NACC) for different forms of multiple sclerosis (MS) using diffusion tensor and proton magnetic resonance (MR) spectroscopic imaging. METHODS A total of 47 patients with MS and 15 controls were included. Regions of interest from the NACC were manually segmented using high resolution anatomic...

1) The coordinates of the Centroid of the Molecule 2) The translational friction tensor 3) The translational/rotational coupling friction tensor in the Center of Resistance 4) The coordinates of the Center of Resistance 5) The rotational friction tensor in the Center of Resistance 6) The Translational diffusion tensor in the Center of Mobility 7) The translational/rotational coupling diffusion ...

Introduction Diffusion kurtosis tensor imaging provides additional information compared with diffusion tensor imaging [1,2]. Solving the kurtosis tensor, however, requires measurements in at least 15 diffusion-encoding directions as well as measurements with at least three or more b-values in each of these directions [2]. This leads to scanning times in the order of 6-10 minutes, which is often...

Background Diffusion tensor imaging (DTI), a gaussian anisotropic diffusion model, provides mean diffusivity (MD) and fractional anisotropy (FA) metrics that describe diffusion in brain tissue (white and gray matter). However, the widely recognized non-gaussian diffusion behavior in tissue has motivated higher order schemes (q-ball, HARDI, DSI) to accurately describe the tissue structure. In ge...