The effective diffusion tensor of water, D, measured by diffusion tensor MRI (DT-MRI), is inherently a discrete, noisy, voxel-averaged sample of an underlying macroscopic effective diffusion tensor field, D(x). Within fibrous tissues this field is presumed to be continuous and smooth at a gross anatomical length scale. Here a new, general mathematical framework is proposed that uses measured DT...

OBJECTIVE Diffusion imaging techniques such as DTI and HARDI are difficult to implement in infants because of their sensitivity to subject motion. A short acquisition time is generally preferred, at the expense of spatial resolution and signal-to-noise ratio. Before estimating the local diffusion model, most pre-processing techniques only register diffusion-weighted volumes, without correcting ...

In vivo diffusion tensor imaging of normal rat spinal cord was performed using a multi-segmented, blipped EPI sequence at 7 T field strength. At high diffusion weighting, the signal exhibited a non-monoexponential decay that was fitted to a biexponential function, associated with the fast and slow components of diffusion in the cord tissue, using a nonlinear regression analysis along with a con...

PURPOSE To evaluate the feasibility of renal diffusion tensor imaging and determine the normative fractional anisotropy and apparent diffusion coefficient values at 3 Tesla magnetic resonance imaging (MRI) using parallel imaging and free breathing technique. MATERIALS AND METHODS A total of 52 young healthy volunteers with no history of renal disease were included in the study. MRI examinatio...

BACKGROUND Olfactory ensheathing cell transplantation is a promising treatment for spinal cord injury. Diffusion tensor imaging has been applied to assess various kinds of spinal cord injury. However, it has rarely been used to evaluate the beneficial effects of olfactory ensheathing cell transplantation. This study aimed to explore the feasibility of diffusion tensor imaging in the evaluation ...

Water diffusion is anisotropic in organized tissues such as white matter and muscle. Diffusion tensor imaging (DTI), a non-invasive MR technique, measures water self-diffusion rates and thus gives an indication of the underlying microstructure of tissue. The diffusion rate is often expressed by a second-order tensor. Visualizing DTI in an insightful way is challenging because of the high dimens...

Diffusion-weighted and diffusion tensor imaging (DWI/DTI) has revolutionized clinical neuroimaging. Pathology may be detected earlier and with greater specificity than with conventional magnetic resonance imaging sequences. In addition, DWI/DTI allows exploring the microarchitecture of the brain. A detailed knowledge of the basics of DWI/DTI is mandatory to better understand pathology encounter...

Fractional anisotropy (FA), defined as the distance of a diffusion tensor from its closest isotropic tensor, has been extensively studied as quantitative anisotropy measure for diffusion tensor magnetic resonance images (DT-MRI). It has been used to reveal the white matter profile of brain images, as guiding feature for seeding and stopping in fiber tractography and for the diagnosis and assess...

In diffusion tensor imaging (DTI) an effective diffusion tensor in each voxel is measured by using a set of diffusion-weighted images (DWIs) in which diffusion gradients are applied in a multiplicity of oblique directions. However, to estimate the diffusion tensor accurately, one must account for the effects of all imaging and diffusion gradient pulses on each signal echo, which are embodied in...