Improved combination of spiral-in/out images for BOLD fMRI
Improved combination of spiral-in/out images for BOLD fMRI
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DOI：
10.1002/mrm.20016
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发表时间：
2004-04-01
影响因子：
3.3
通讯作者：
Thomason, ME
中科院分区：
文献类型：
--
作者：
Glover, GH;Thomason, ME
使用螺旋入/出技术进行采集会产生在螺旋入和螺旋出轨迹期间获得的两个独立的图像时间序列。在均匀的大脑区域中，这两个组件具有可比较的信号和大胆的对比度，并且可以进行平均，但在受到磁化率效应影响的区域中，两个图像中的信号和噪声都可能不同，其他组合方法可能更有效。这里，使用言语工作记忆（七名受试者）和以 3 T 扫描的屏气任务（六名受试者）对全脑和前额叶皮层的信号和激活对比恢复进行了比较。结果发现，基于分别从螺旋入和螺旋出图像导出的激活图的统计加权组合提供的激活体积比第二选择信号加权组合增加了 33-59%，比单独螺旋出采集增加了 100-200%，并且简单平均不如信号加权组合。 (C) 2004 Wiley-Liss, Inc.
Acquisitions with the spiral-in/out technique result in two separate image timeseries obtained during the spiral-in and spiral-out trajectory. In uniform brain regions the two components have comparable signal and BOLD contrast and can be averaged, but in regions compromised by susceptibility effects where both signal and noise can differ in the two images other combination methods may be more effective. Here, several weighting schemes are compared for signal and activation contrast recovery in whole brain and prefrontal cortex using verbal working memory (seven subjects) and breathholding tasks (six subjects) scanned at 3 T. It was found that a statistically weighted combination based on activation maps derived separately from the spiral-in and spiral-out images provides activation volumes with increases of 33-59% over second-choice signal-weighted combination and 100-200% increases over spiral-out acquisition alone, and that simple averaging is inferior to signal-weighted combination. (C) 2004 Wiley-Liss, Inc.