This paper describes a new NMR imaging modality--MR diffusion tensor imaging. It consists of estimating an effective diffusion tensor, Deff, within a voxel, and then displaying useful quantities derived from it. We show how the phenomenon of anisotropic diffusion of water (or metabolites) in anisotropic tissues, measured noninvasively by these NMR methods, is exploited to determine fiber tract ...

Abstract Partial differential equations (PDE’s) have dominated image processing research recently (see Suri et al. [1], [2], [3], [4], [5], [6] and Haker [7]). The three main reasons for their success are: (1) their ability to transform a segmentation modeling problem into a partial differential equation framework and their ability to embed and integrate different regularizers into these models...

The accuracy and interpretation of results obtained by Diffusion Tensor Imaging (DTI) are largely influenced by several experimental parameter settings. In Voxel-Based (VB) analysis images are smoothed, in order to improve their Signal to Noise Ratio (SNR) and to reduce the impact of normalization and artifacts. This is a critical step and care must be taken so that directional information and ...

PURPOSE To analyze diffusional anisotropy in frontal and occipital white matter of human brain quantitatively as a function of age by using diffusion-weighted MR imaging. METHODS Ten neonates (< 1 month), 13 infants (1-10 months), 9 children (1-11 years), and 16 adults (20-79 years) were examined. After taking axial spin-echo images of the brain, diffusion-sensitive gradients were added paral...

This paper presents an efficient method for feature definition and classification on shapes. We tackle this challenge by exploring the weighted harmonic field (WHF), which is also the stable state of a heat diffusion regulated by an anisotropic diffusion tensor. The technical merit of our method is highlighted by the elegant integration of locallydefined diffusion tensor and globally-defined ha...

The Perona–Malik (PM) model, a classical anisotropic diffusion, can preserve edges while removing the noise. However, the defect of traditional PM model is tending to contain the staircase effect in the processed image. For this reason, a novel ramp preserving Perona–Malik (RPPM) model based on a new edge indicator is presented. In the RPPM model, the diffusion coefficient of the PM model is ad...

The study of inflammatory disease hinges upon the behavior and movement of leukocytes and their interaction with the endothelium. We put forth a method for tracking leukocytes in vivo, whereas tracking has been demonstrated previously only for in vitro experiments. The tracker is based on the enhancing capability of morphological anisotropic diffusion, a partial differential equation model for ...

Functional magnetic resonance imaging (fMRI) uses MRI to noninvasively map areas of increased neuronal activity in human brain without the use of an exogenous contrast agent. Low signal-to-noise ratio of fMRI images makes it necessary to use sophisticated image processing techniques, such as statistical parametric map (SPM), to detect activated brain areas. This paper presents a new technique t...

Existing integer-order Nonlinear Anisotropic Diffusion NAD used in noise suppressing will produce undesirable staircase effect or speckle effect. In this paper, we propose a new scheme, named Fractal-order Perona-Malik Diffusion FPMD , which replaces the integer-order derivative of the Perona-Malik PM Diffusion with the fractional-order derivative using G-L fractional derivative. FPMD, which is...

We present a system of PDEs for image restoration, which consists of an anisotropic diffusion equation driven by a diffusion tensor, whose structure depends on the gradient of the image obtained from a coupled time-delay regularization equation, and governs the direction and the speed of the diffusion. The diffusion resulting from this model is isotropic inside a homogeneous region, anisotropic...