Detection of Microscopic Diffusion Anisotropy on a Whole-Body MR System With Double Wave Vector Imaging
Detection of Microscopic Diffusion Anisotropy on a Whole-Body MR System With Double Wave Vector Imaging
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DOI：
10.1002/mrm.22934
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发表时间：
2011-11-01
影响因子：
3.3
通讯作者：
Finsterbusch, Juergen
中科院分区：
文献类型：
--
作者：
Lawrenz, Marco;Finsterbusch, Juergen
双波矢量扩散加权实验可以检测微观水平上的扩散各向异性，例如。例如，可以区分较低的纤维密度和降低的纤维相干性。在垂直孔 MR 系统 (>= 500mTm(-1)) 上观察到平行和正交波矢量方向之间的潜在信号差异；然而，数值模拟表明，典型的全身 MR 梯度脉冲持续时间预计会大大减少。在此，在 3 T 临床 MR 系统 (40mTm(-1)) 上对猪脊髓组织和参考液体模型进行了研究。通过对不同的绝对波矢量方向进行平均，由背景梯度场和涡流等实验缺陷引起的信号变化被最小化，并且可以评估旋转不变的各向异性测量。即使在垂直于脊髓的平面中，在灰质和白质组织中也观察到显着的微观各向异性，这与之前的垂直孔实验一致。因此，证明双波矢量实验可以研究全身磁共振系统的微观各向异性。 Magn Reson Med 66: 1405-1415, 2011。(C) 2011 Wiley periodicals, Inc.
Double-wave-vector diffusion-weighting experiments can detect diffusion anisotropy on a microscopic level which, e. g., could distinguish lower fiber densities from reduced fiber coherence. The underlying signal difference between parallel and orthogonal wave vector orientations has been observed on vertical-bore MR systems (>= 500mTm(-1)); however, numerical simulations reveal that it is expected to be considerably reduced for typical whole-body MR gradient pulse durations. Here, pig spinal cord tissue and a reference fluid phantom were investigated on a 3 T clinical MR system (40mTm(-1)). By averaging over different absolute wave vector orientations, signal variations caused by experimental imperfections like background gradient fields and eddy currents were minimized and a rotationally invariant anisotropy measure could be assessed. A significant microscopic anisotropy was observed in gray and white matter tissue even in the plane perpendicular to the cord which is consistent with previous vertical-bore experiments. Thus, it is demonstrated that double-wave-vector experiments can investigate the microscopic anisotropy on whole-body MR systems. Magn Reson Med 66: 1405-1415, 2011. (C) 2011 Wiley Periodicals, Inc.