We propose a novel large deformation diffeomorphic registration algorithm to align high angular resolution diffusion images (HARDI) characterized by Orientation Distribution Functions (ODF). Our proposed algorithm seeks an optimal diffeomorphism of large deformation between two ODF fields in a spatial volume domain and at the same time, locally reorients an ODF in a manner such that it remains ...

Fiber orientation is the key information in diffusion tractography. Several deconvolution methods have been proposed to obtain fiber orientations by estimating a fiber orientation distribution function (ODF). However, the L 2 regularization used in deconvolution often leads to false fibers that compromise the specificity of the results. To address this problem, we propose a method called diffus...

How to estimate the diffusion Ensemble Average Propagator (EAP) from the DWI signals in q-space is an open problem in diffusion MRI field. Many methods were proposed to estimate the Orientation Distribution Function (ODF) that is used to describe the fiber direction. However, ODF is just one of the features of the EAP. Compared with ODF, EAP has the full information about the diffusion process ...

In this article we develop a new method to segment Q-Ball imaging (QBI) data. We first estimate the orientation distribution function (ODF) using a fast and robust spherical harmonic (SH) method. Then, we use a region-based statistical surface evolution on this image of ODFs to efficiently find coherent white matter fiber bundles. We show that our method is appropriate to propagate through regi...

High angular resolution diffusion imaging (HARDI) permits the computation of water molecule displacement probabilities over a sphere of possible displacement directions. This probability is often referred to as the orientation distribution function (ODF). In this paper we present a novel model for the diffusion ODF namely, a mixture of von Mises-Fisher (vMF) distributions. Our model is compact ...

The acquisition of high angular resolution diffusion MRI is particularly long and subject motion can become an issue. The orientation distribution function (ODF) can be reconstructed online incrementally from diffusion-weighted MRI with a Kalman filtering framework. This online reconstruction provides real-time feedback throughout the acquisition process. In this article, the Kalman filter is f...

he article presents the results of a study influence plastic deformation on change in coefficients orientation distribution function (ODF) W400 and W420 low-alloy steel 09G2S. To calculate ODF coefficients, velocities times propagation shear longitudinal bulk elastic waves their ratios were used. The physical interpretation is given. coefficient depicts effect birefringence waves, ratio linearl...

INTRODUCTION: High angular resolution diffusion imaging (HARDI) requires more diffusion-weighted (DW) measurements than traditional diffusion tensor imaging acquisitions, but it can resolve some fibre crossings. This comes at the price of a longer acquisition time, which can be problematic for clinical studies involving children and people inflicted with certain diseases. Excessive motion of th...

A method of decomposition of overlapping reflections in a powder pattern with the aid of preferred orientation is presented. Empirical preferred orientation correction with axial symmetry is used. The method is tested on several sets of simulated powder patterns. Introduction Powder patterns collected at various values of some parameter which influences either the position or the intensity of t...

We propose a deterministic and a probabilistic extension of classical diffusion tensor imaging (DTI) tractography algorithms based on a sharp fiber orientation distribution function (ODF) reconstruction from Q-Ball Imaging (QBI). An important contribution of the paper is the integration of some of the latest state-of-the-art high angular resolution diffusion imaging (HARDI) data processing meth...