MR Diffusion Tensor Imaging: A Window into White Matter Integrity of the Working Brain

Abstract

As Norman Geschwind asserted in 1965, syndromes resulting from white matter lesions could produce deficits in higher-order functions and "disconnexion" or the interruption of connection between gray matter regions could be as disruptive as trauma to those regions per se. The advent of in vivo diffusion tensor imaging, which allows quantitative characterization of white matter fiber integrity in health and disease, has served to strengthen Geschwind's proposal. Here we present an overview of the principles of diffusion tensor imaging (DTI) and its contribution to progress in our current understanding of normal and pathological brain function.

Tract-Specific Fractional Anisotropy Predicts Cognitive Outcome in a Community Sample of Middle-Aged Participants with White Matter Lesions

“…9,10 The application of a voxel-based approach in this study circumvents the potential limitations of region of interest methodology for DTI analysis, such as subjective operatordependent placement, limited reliability and reproducibility, and partial volume effects. 9,39 It also overcomes the lack of information on a regional level of segmentation methods. 11 In particular, the Tract-Based Spatial Statistics procedure that we applied has been developed to retain the strengths of voxel-based analysis while addressing registration and smoothing issues that are potential pitfalls of data preprocessing for such approach.…”

Diffusion Tensor Imaging Analysis for Psychiatric Disorders

“…However, VBA is less sensitive than ROI analysis for quantiˆcation because spatial normalization can be imperfect and some residual morphometric diŠerences may persist. 7 These diŠerences are not seen with tract-based spatial statistics (TBSS) (Oxford University, Nu‹eld Department of Clinical Neurosciences, UK), another software package, that attempts to avoid such problems completely by using a``mean FA skeleton'' to represent the centers ofˆbers that are common to all humans. 7 …”

White matter microstructure in boys with persistent depressive disorder

“…In addition, axonal (AD) and radial diffusivity (RD) corresponding to movement along and across fibre bundles respectively can also be determined. FA is frequently reported in studies of white matter microstructure and lower FA is often interpreted as a reduction in myelination but it may equally correspond to differences in axon diameter, fiber bundle density, crossing fibers, myelin thickness or the cytoskeleton (Chanraud, Zahr, Sullivan, & Pfefferbaum, 2010;Jones, Knosche, & Turner, 2013;Winston, 2012).…”