3D Single-Shot VASO Using a Maxwell Gradient Compensated GRASE Sequence
3D Single-Shot VASO Using a Maxwell Gradient Compensated GRASE Sequence
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DOI：
10.1002/mrm.22000
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发表时间：
2009-07-01
影响因子：
3.3
通讯作者：
Norris, David G.
中科院分区：
文献类型：
--
作者：
Poser, Benedikt A.;Norris, David G.
血管空间占用（VASO）方法最近被提出作为功能性MRI（fMRI）方法，能够检测激活相关的血容量（CBV）变化，而不需要血池造影剂。在目前的工作中，我们介绍了一种新的全脑VASO技术，该技术是基于并行加速的单次拍摄3D GRASE（梯度和自旋回波）读出。GRASE VASO序列对伴随的麦克斯韦梯度采用流量补偿校正方案，这是避免由于违反非共振激发的Carr-Purcell-Meiboom-Gill（CPMG）条件而可能发生的拖尾伪影所必需的。在8名受试者上进行了6分钟视觉运动刺激的实验。在P < 0.01时，视觉刺激的平均信号变化百分比和t评分分别为-3.11%和-8.42;检测到左右运动皮层和辅助运动区的激活分别为-2.75%和-6.70。敏感性和信号变化与基于回波平面成像（EPI）的单层VASO相当，如额外的视觉任务实验所示（-3.39%和-6.93）。该方法使得基于CBV对比进行全脑认知激活研究成为可能。Magn Reson Med 62：255-262，2009. (C)2009 Wiley-Liss，Inc.
The vascular space occupancy (VASO) method was recently proposed as a functional MRI (fMRI) method that is capable of detecting activation-related changes in blood volume (CBV), without the need for a blood-pool contrast agent. In the present work we introduce a new whole-brain VASO technique that is based on a parallel-accelerated single-shot 3D GRASE (gradient and spin echo) readout. The GRASE VASO sequence employs a flow-compensated correction scheme for concomitant Maxwell gradients which is necessary to avoid smearing artifacts that may occur due to violation of the Carr-Purcell-Meiboom-Gill (CPMG) condition for off-resonance excitation. Experiments with 6 min of visual-motor stimulation were performed on eight subjects. At P < 0.01, average percent signal change and t-score for visual stimulation were -3.11% and -8.42, respectively; activation in left and right motor cortices and supplementary motor area was detected with -2.75% and -6.70, respectively. Sensitivity and signal changes are comparable to those of echo-planar imaging (EPI)-based single-slice VASO, as indicated by additional visual-task experiments (-3.39% and -6.93). The method makes it possible to perform whole-brain cognitive activation studies based on CBV contrast. Magn Reson Med 62:255-262, 2009. (C) 2009 Wiley-Liss, Inc.