篇名 | Effects of b-Value and Echo Time on Magnetic Resonance Diffusion Tensor Imaging-Derived Parameters at 1.5 T: A Voxel-Wise Study |
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卷期 | 33:1 |
作者 | Chou, Ming-chung 、 Kao, E-fong 、 Susumu Mori |
頁次 | 045-050 |
關鍵字 | Diffusion weighting factor 、 Echo time 、 diffusion tensor imaging 、 Axial diffusivity 、 Radial diffusivity 、 Mean diffusivity 、 Fractional anisotropy 、 Principal eigenvector 、 Reproducibility 、 Accuracy 、 EI 、 SCI |
出刊日期 | 201302 |
The diffusion weighting factor (b-value) and echo time (TE) are two important parameters that influence quantitative measurements of diffusion tensor imaging (DTI). The present study employs a voxel-wise post-processing scheme to investigate the effects of b-value and TE on the reproducibility and accuracy of DTI-derived indices based on actual human brain data with commonly used imaging parameters. Five repeated DTI datasets of six b-values and five TE values were acquired from a healthy subject. The reproducibility and accuracy of axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), fractional anisotropy (FA), and the principal eigenvector (PEV) are assessed by calculating the voxel-wise standard deviation, coefficient of variance, and difference of mean values from the reference DTI dataset acquired with number of excitations (NEX) = 15. The results show that the reproducibility and accuracy of AD, RD, MD, FA, and PEV are significantly impacted by b-value and TE, and that there is a significant difference between gray and white matter tissues. Therefore, the reproducibility and accuracy of DTI-derived indices depends on the b-value and TE for both gray and white matter.