Three dimensional echo-planar imaging at 7 Tesla.
Three dimensional echo-planar imaging at 7 Tesla.
复制标题
DOI：
10.1016/j.neuroimage.2010.01.108
复制
发表时间：
2010-05-15
期刊：
影响因子：
5.7
通讯作者：
Barth, M.
中科院分区：
文献类型：
--
作者：
Poser, B. A.;Koopmans, P. J.;Witzel, T.;Wald, L. L.;Barth, M.
功能 MRI (fMRI) 最常采用 2D 平面回波成像 (EPI)。日益流行的超高场强所带来的 fMRI 优势在高分辨率采集中得到了最好的利用，但由于多种原因，2D EPI 变得不切实际，其中包括非常长的体积采集时间。在这项 7 T 的研究中，实现了沿两个相位编码轴具有完全并行和部分傅里叶成像能力的 3D EPI 序列，并用于评估 3D 和相应 2D EPI 采集在四种不同空间分辨率（从小到典型体素尺寸（1.5-3.0mm 各向同性））下的灵敏度。全脑静息态测量 (N=4) 显示 3D 方法对灰质和白质具有更好的或至少相当的灵敏度。 3D 对生理效应的较大脆弱性被更短的体积 TR 所抵消，这还允许在事件相关 fMRI 完全可接受的范围内以高分辨率覆盖整个大脑：1.5 毫米的 TR 仅为 3.07 秒，2.0 毫米的 1.88 秒，2.5 毫米的 1.38 秒，3.0 毫米各向同性分辨率的 1.07 秒。为了研究检测和空间解析视觉皮层中 BOLD 激活的能力，以 1mm 各向同性分辨率和 3×3 的并行成像加速度进行功能性 3D EPI 实验（N = 8），导致全脑覆盖的 TR 仅 3.2 秒。根据我们的结果以及本研究中发现的 3D 相对于 2D EPI 的其他几个实际优势，我们得出结论，3D EPI 为 7 特斯拉的全脑 fMRI 提供了有用的替代方案，而不仅仅是在需要高分辨率数据时。
Functional MRI (fMRI) most commonly employs 2D echo-planar imaging (EPI). The advantages for fMRI brought about by the increasingly popular ultra-high field strengths are best exploited in high-resolution acquisitions, but here 2D EPI becomes unpractical for several reasons, including the very long volume acquisitions times. In this study at 7 T, a 3D EPI sequence with full parallel and partial Fourier imaging capability along both phase encoding axes was implemented and used to evaluate the sensitivity of 3D and corresponding 2D EPI acquisitions at four different spatial resolutions ranging from small to typical voxel sizes (1.5–3.0mm isotropic). Whole-brain resting state measurements (N=4) revealed a better, or at least comparable sensitivity of the 3D method for gray and white matter. The larger vulnerability of 3D to physiological effects was outweighed by the much shorter volume TR, which moreover allows whole brain coverage at high resolution within fully acceptable limits for event-related fMRI: TR was only 3.07s for 1.5 mm, 1.88 s for 2.0mm, 1.38 s for 2.5 mm and 1.07s for 3.0 mm isotropic resolution. In order to investigate the ability to detect and spatially resolve BOLD activation in the visual cortex, functional 3D EPI experiments (N=8) were performed at 1mm isotropic resolution with parallel imaging acceleration of 3×3, resulting in a TR of only 3.2s for whole-brain coverage. From our results, and several other practical advantages of 3D over 2D EPI found in the present study, we conclude that 3D EPI provides a useful alternative for whole-brain fMRI at 7 Tesla, not only when high-resolution data are required.
登录
查看更多内容
影响因子：
5.7
作者：
Jenkinson, M;Bannister, P;Smith, S
通讯作者：
Smith, S
影响因子：
3.3
作者：
Lai, S;Glover, GH
通讯作者：
Glover, GH
影响因子：
4.8
作者：
Smith, SM
通讯作者：
Smith, SM
影响因子：
3.3
作者：
Griswold, MA;Jakob, PM;Haase, A
通讯作者：
Haase, A
影响因子：
3.3
作者：
de Zwart, JA;van Gelderen, P;Duyn, JH
通讯作者：
Duyn, JH