In this study, we evaluate the performance of a flow-based surface evolution fiber tracking algorithm by means of a physical anisotropic diffusion phantom with known connectivity. We introduce a novel speed function for surface evolution that is derived from either diffusion tensor (DT) data, high angular resolution diffusion (HARD) data, or a combined DT-HARD hybrid approach. We use the model-...

L-C. Chang, C. Pierpaoli, P. J. Basser NICHD, NIH, Bethesda, MD, United States Introduction: In typical applications of diffusion tensor MRI (DTI), DT-derived quantities are used to make a diagnostic, therapeutic or scientific determination. In such cases, it is essential to characterize the variability of these tensor-derived quantities. Parametric [1] and empirical methods (e.g., Monte Carlo ...

Introduction. Diffusion tensor (DT) MRI allows to obtain indices of white matter (WM) integrity. A method to obtain estimates of WM fiber bundle volumes using DT MRI has also been developed [1]. Investigating the relationship between simultaneous age effects on different diffusivity parameters could provide more insight into the mechanisms of WM aging [2]. In this study, we investigate linear a...

In this paper a noniterative algorithm to be used for the analytical determination of the sorted eigenvalues and corresponding orthonormalized eigenvectors obtained by diffusion tensor magnetic resonance imaging (DT-MRI) is described. The algorithm uses the three invariants of the raw water spin self-diffusion tensor represented by a 3 x 3 positive definite matrix and certain math functions tha...

The aim of the present study was to apply diffusion tensor MRI (DT-MRI), a quantitative MRI measure which reflects tissue organization, to dementia with Lewy bodies (DLB). DT-MRI scans were obtained from 15 patients with probable DLB and 10 sex- and age-matched healthy controls. Abnormalities were found in the corpus callosum, pericallosal areas and the frontal, parietal, occipital and, less pr...

In this paper we present a volumetric approach for quantitatively studying white matter connectivity from diffusion tensor magnetic resonance imaging (DT-MRI). The proposed method is based on a minimization of path cost between two regions, defined as the integral of local costs that are derived from the full tensor data along the path. We solve the minimal path problem using a Hamilton-Jacobi ...

Nuclear magnetic resonance (MR) (NMR) is commonly used for the determination of rock porosity, as well pore size distribution (PSD) and tortuosity, required to handle hydrocarbon exploitation. Emerging technologies NMR equipment now enable visualization porosity using imaging (MRI). Currently, single-point most common MRI technique employed, but diffusion-weighted has been attracting attention ...

The effect of human fetal heart geometry and anisotropy on anatomy induced drift and self-termination of cardiac re-entry is studied here in MRI based 2D slice and 3D whole heart computer simulations. Isotropic and anisotropic models of 20 weeks of gestational age human fetal heart obtained from 100 μm voxel diffusion tensor MRI data sets were used in the computer simulations. The fiber orienta...

Image segmentation is a method of separating an image into regions of interest, such as separating an object from the background. The random walker image segmentation technique has been applied extensively to scalar images and has demonstrated robust results. In this paper we propose a novel method to apply the random walker method to segmenting non-scalar diffusion tensor magnetic resonance im...

The human brain undergoes rapid and dynamic development early in life. Assessment of brain growth patterns relevant to neurological disorders and disease requires a normative population model of growth and variability in order to evaluate deviation from typical development. In this paper, we focus on maturation of brain white matter as shown in diffusion tensor MRI (DT-MRI), measured by fractio...