High-resolution human diffusion tensor imaging using 2-D navigated multishot SENSE EPI at 7 T.
High-resolution human diffusion tensor imaging using 2-D navigated multishot SENSE EPI at 7 T.
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DOI：
10.1002/mrm.24320
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发表时间：
2013-03-01
影响因子：
3.3
通讯作者：
Anderson, Adam W.
中科院分区：
文献类型：
--
作者：
Jeong, Ha-Kyu;Gore, John C.;Anderson, Adam W.
并行成像与部分傅立叶采集的组合极大地改善了扩散加权单次激发EPI的性能，并且是在低至中等磁场强度（例如1.5或3特斯拉）下采集的首选方法。然而，在7特斯拉下，增加的非共振效应和减少的横向弛豫时间会产生比在较低磁场强度下更显著的伪影，并限制数据采集。使用多次激发方法的k空间遍历的额外加速（其在每次激发之后采集k空间数据的子集）相对于常规的单次激发采集减少了这些伪影。然而，由于相位混叠，在加速的扩散加权多激发EPI中，对运动引起的相位误差的校正并不简单。在这项研究中，我们介绍了一种简单的采集和相应的重建方法，扩散加权多激发EPI与平行成像适用于高场。重建使用标准SENSE算法的简单修改来解释拍摄到拍摄的相位误差;该方法被称为使用图像空间采样函数的图像重建（IRIS）。使用这种方法，从高度混叠的在体内图像数据，使用2-D导航相位信息的重建被证明为人体扩散加权成像研究在7特斯拉。最终重建的图像显示亚毫米级的面内分辨率，没有重影，模糊和非共振伪影大大减少。
The combination of parallel imaging with partial Fourier acquisition has greatly improved the performance of diffusion-weighted single-shot EPI and is the preferred method for acquisitions at low to medium magnetic field strength such as 1.5 or 3 Tesla. Increased off-resonance effects and reduced transverse relaxation times at 7 Tesla, however, generate more significant artifacts than at lower magnetic field strength and limit data acquisition. Additional acceleration of k-space traversal using a multi-shot approach, which acquires a subset of k-space data after each excitation, reduces these artifacts relative to conventional single-shot acquisitions. However, corrections for motion-induced phase errors are not straightforward in accelerated, diffusion-weighted multi-shot EPI because of phase aliasing. In this study, we introduce a simple acquisition and corresponding reconstruction method for diffusion-weighted multi-shot EPI with parallel imaging suitable for use at high field. The reconstruction uses a simple modification of the standard SENSE algorithm to account for shot-to-shot phase errors; the method is called Image Reconstruction using Image-space Sampling functions (IRIS). Using this approach, reconstruction from highly aliased in vivo image data using 2-D navigator phase information is demonstrated for human diffusion-weighted imaging studies at 7 Tesla. The final reconstructed images show submillimeter in-plane resolution with no ghosts and much reduced blurring and off-resonance artifacts.
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DOI：
10.1006/jmrb.1994.1037
发表时间：
1994-03-01
期刊：
JOURNAL OF MAGNETIC RESONANCE SERIES B
影响因子：
--
作者：
BASSER, PJ;MATTIELLO, J;LEBIHAN, D
通讯作者：
LEBIHAN, D
影响因子：
3.3
作者：
JEZZARD, P;BALABAN, RS
通讯作者：
BALABAN, RS
影响因子：
3.3
作者：
Bammer, R;Keeling, SL;Fazekas, F
通讯作者：
Fazekas, F
影响因子：
3.3
作者：
DECRESPIGNY, AJ;MARKS, MP;MOSELEY, ME
通讯作者：
MOSELEY, ME
影响因子：
3.3
作者：
Griswold, MA;Jakob, PM;Haase, A
通讯作者：
Haase, A