How to correct susceptibility distortions in spin-echo echo-planar images: application to diffusion tensor imaging
How to correct susceptibility distortions in spin-echo echo-planar images: application to diffusion tensor imaging
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DOI：
10.1016/s1053-8119(03)00336-7
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发表时间：
2003-10-01
期刊：
影响因子：
5.7
通讯作者：
Ashburner, J
中科院分区：
文献类型：
--
作者：
Andersson, JLR;Skare, S;Ashburner, J
扩散张量成像通常是通过获取一系列具有不同方向扩散梯度的扩散加权自旋回波平面图像来执行的。平面回波图像的一个问题是在不同磁化率的组织之间获得接近接合处的几何失真。这导致了扭曲的扩散-张量映射。为了解决这个问题，我们建议为每个扩散梯度获取两个图像；一个是自下而上的，另一个是在相位编码方向上对k空间的自上而下的遍历。这同时实现了提供关于基本位移场和强度图的信息的目标，即使在扭曲区域也具有足够的空间采样密度。与使用常规3D MR技术获取的图像体积相比，所得到的DT图显示出相当高的几何保真度。(C)2003 Elsevier Inc.保留所有权利。
Diffusion tensor imaging is often performed by acquiring a series of diffusion-weighted spin-echo echo-planar images with different direction diffusion gradients. A problem of echo-planar images is the geometrical distortions that obtain near junctions between tissues of differing magnetic susceptibility. This results in distorted diffusion-tensor maps. To resolve this we suggest acquiring two images for each diffusion gradient; one with bottom-up and one with top-down traversal of k-space in the phase-encode direction. This achieves the simultaneous goals of providing information on the underlying displacement field and intensity maps with adequate spatial sampling density even in distorted areas. The resulting DT maps exhibit considerably higher geometric fidelity, as assessed by comparison to an image volume acquired using a conventional 3D MR technique. (C) 2003 Elsevier Inc. All rights reserved.