Whole brain, high resolution multiband spin-echo EPI fMRI at 7 T: A comparison with gradient-echo EPI using a color-word Stroop task
Whole brain, high resolution multiband spin-echo EPI fMRI at 7 T: A comparison with gradient-echo EPI using a color-word Stroop task
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DOI：
10.1016/j.neuroimage.2014.04.011
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发表时间：
2014-08-15
期刊：
影响因子：
5.7
通讯作者：
Norris, David G.
中科院分区：
文献类型：
--
作者：
Boyacioglu, Rasim;Schulz, Jenni;Norris, David G.
在7T下实现了一个具有高空间分辨率(1.5mM各向同性)和高时间分辨率(时间分辨率为2 S)的全脑多波段自旋回波平面成像序列，并使用颜色词Stroop任务评估其总体性能(tSNR、灵敏度和信噪比)，并与几何匹配的梯度回波(GE)多波段序列(TR1.4 S)进行比较。Pins RF脉冲用于重新聚焦，以降低对RF幅度的要求，而SAR、求和和相位优化的标准脉冲用于激励，从而实现横向或倾斜切片方向。通过在相位编码方向上使用并行成像和采集后的失真校正，失真被最小化。总体而言，GE-EPI在大多数脑区显示出更高的效率和更高的CNR，但在群体和个体受试者水平上，除了视觉皮质和额上极的部分区域外，GE-EPI显示出更高的效率和更高的CNR。梯度回波EPI能够检测到空气/组织界面附近的强劲激活，例如眼眶-额叶和皮质下区域，这是由于使用的薄层和高平面分辨率减少了体素内的消相。(C)2014 Elsevier Inc.保留所有权利。
A whole brain, multiband spin-echo (SE) echo planar imaging (EPI) sequence employing a high spatial (1.5 mm isotropic) and temporal (TR of 2 s) resolution was implemented at 7 T. Its overall performance (tSNR, sensitivity and CNR) was assessed and compared to a geometrically matched gradient-echo (GE) EPI multiband sequence (TR of 1.4 s) using a color-word Stroop task. PINS RF pulses were used for refocusing to reduce RF amplitude requirements and SAR, summed and phase-optimized standard pulses were used for excitation enabling a transverse or oblique slice orientation. The distortions were minimized with the use of parallel imaging in the phase encoding direction and a post-acquisition distortion correction. In general, GE-EPI shows higher efficiency and higher CNR in most brain areas except in some parts of the visual cortex and superior frontal pole at both the group and individual-subject levels. Gradient-echo EPI was able to detect robust activation near the air/tissue interfaces such as the orbito-frontal and subcortical regions due to reduced intra-voxel dephasing because of the thin slices used and high in-plane resolution. (C) 2014 Elsevier Inc. All rights reserved.