Background and Aim: DTI-based tractography could help us to visualize the spatial relation of fiber tracts to brain lesions. Several factors may interfere with the procedure of diffusion-based tractography, especially in brain tumors. The aim of the current study is to discuss several solutions to improve the procedure of fiber reconstruction adjacent or inside brain lesions. Illustrative cases...

The contrast provided by diffusion MRI has been exploited repeatedly for in vivo segmentations of thalamic nuclei. This paper systematically investigates the benefits of high-angular resolution (HARDI) data for this purpose. An empirical analysis of clustering stability reveals a clear advantage of acquiring HARDI data at b = 1000 s/mm2. However, based on stability arguments, as well as further...

We denoise High Angular Resolution Diffusion Imaging (HARDI) data, a necessary step for reconstruction of fibers and pathways in the living brain. HARDI gives more accurate information than diffusion tensor imaging (DTI) and allows to reconstruct highly complex fiber architecture. Intensity data is given at all voxels and directions on the sphere. A tuning parameter b is used to collect the dat...

We introduce a framework for population analysis of white matter tracts in diffusion weighted images. Our pipeline computes fibers from high angular resolution diffusion imaging (HARDI) images; it clusters the fibers incorporating prior knowledge from an atlas; the method then represents each fiber bundle compactly using a path following points of highest density (maximum density path; MDP); an...

Imaging genetics is a new field that extends methods from quantitative genetics to handle brain images. Its goal is to identify features of the brain that are genetically influenced, and then find specific variations at the genomic level that contribute to them. Recent studies using diffusion tensor imaging (DTI) in twins have discovered specific genomic variations that influence standard DTI-d...

Introduction and Background. High angular resolution distribution diffusion imaging (HARDI) implicitly captures information about the structure in which the diffusion process takes place. HARDI allows examination of relatively wide range of diffusion signal angular frequencies that, due to the complexity of both diffusion process and its milieu, may spread over multiple bands. In consequence, w...

In High Angular Resolution Diffusion Imaging (HARDI), Orientation Distribution Function (ODF) and Ensemble Average Propagator (EAP) are two important Probability Density Functions (PDFs) which reflect the water diffusion and fiber orientations. Spherical Polar Fourier Imaging (SPFI) is a recent model-free multi-shell HARDI method which estimates both EAP and ODF from the diffusion signals with ...

We describe the visualization of the barrel cortex of the primary somatosensory area (S1) of ex vivo adult mouse brain with short-tracks track density imaging (stTDI). stTDI produced much higher definition of barrel structures than conventional fractional anisotropy (FA), directionally-encoded color FA maps, spin-echo T1- and T2-weighted imaging and gradient echo T1/T2*-weighted imaging. 3D hig...

Genetic analysis of diffusion tensor images (DTI) shows great promise in revealing specific genetic variants that affect brain integrity and connectivity. Most genetic studies of DTI analyze voxel-based diffusivity indices in the image space (such as 3D maps of fractional anisotropy) and overlook tract geometry. Here we propose an automated workflow to cluster fibers using a white matter probab...