%0 Journal Article
%T Diffusion Tensor Metric Measurements as a Function of Diffusion Time in the Rat Central Nervous System
%A Jonathan D. Thiessen
%A Trevor J. Vincent
%A Sheryl L. Herrera and Melanie Martin
%J Magnetic Resonance Insights
%D 2012
%I 
%R 10.4137/MRI.S10692
%X MRI and Monte Carlo simulated data of pulsed gradient spin echo experiments were used to study the effects of diffusion time, gradient strength and b-value on diffusion tensor (DT) metrics using real and simulated fixed rat spines. Radial (¦Ë¡Í) in grey matter and simulation data, axial (¦Ë||) in both grey and white matter in fixed rat spinal cords and mean diffusivity in all tissues showed a significant decrease with diffusion time at b = 1 ¦Ìm2/ms. All diffusivities significantly decreased with b-value at g = 116 mT/m and at ¦¤eff = 23 ms. The fractional anisotropy (FA) significantly increased with diffusion time at b = 1 ¦Ìm2/ms in the simulation data and grey matter. FA significantly increased in white matter and simulation data and significantly decreased in grey matter with b-value at g = 116 mT/m and at  eff = 23 ms. These data suggest that DTI metrics are highly dependent on pulse sequence parameters.
%U http://www.la-press.com/diffusion-tensor-metric-measurements-as-a-function-of-diffusion-time-i-article-a3426