Effect of Diffusion Weighting and Number of Sensitizing Directions on Fiber Tracking in DTI

Abstract

Diffusion Tensor (DT) fiber tracking techniques offer significant potential for studying anatomical connectivity of human brain in vivo. And the reliability and accuracy of fiber tracking results depend on the quality of estimated DT which is determined by parameters of image acquisition protocol. The aim of this paper is to investigate what echo-planar image (EPI) acquisition parameters: the number of sensitizing directions K and diffusion weighting b-value gives the best estimation of DT and shorter scan time. We carried out tracking on synthetic dataset that was artificially corrupted by various levels of Gaussian noise to study the effects of K and b-value on fiber tracking results, and to evaluate the quality of estimated DT. It was found that when K value larger than 13 and b-value larger than 800 smm^{− − 2} best estimated DTs. And further increments of K and b-value had no significant effect on quality of estimated DT.