Fast Imaging Technique for fMRI: Consecutive Multishot Echo Planar Imaging Accelerated with GRAPPA Technique.
Fast Imaging Technique for fMRI: Consecutive Multishot Echo Planar Imaging Accelerated with GRAPPA Technique.
复制标题
功能磁共振成像的快速成像技术：使用Grappa技术加速加速的连续多曲声回声平面成像。
DOI：
10.1155/2015/394213
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发表时间：
2015
影响因子：
--
通讯作者：
Kang CK
中科院分区：
文献类型：
--
作者：
Kang D;Sung YW;Kang CK
本研究旨在评价所提出的连续多激发回波平面成像（cmsEPI）结合并行成像技术在功能成像研究中的信噪比（SNR）和加速度。我们开发了cmsEPI序列，使用连续采集的多拍EPI片段和可变翻转角，以最大限度地减少片段之间的延迟和最大限度地提高信噪比。我们还将cmsEPI与广义自动校准部分并行采集（GRAPPA）方法相结合。在不同的加速因子和节段数下测量时间SNR，以评估功能敏感性。我们还研究了EPI序列中固有的几何失真。实际的加速因子，R = 2或R = 3，所提出的技术，提高了最大的18%，在体模测试和平均8.2%，在体内实验中的时间SNR相比，cmsEPI没有并行成像。数据收集时间也与加速因子成正比地减少。当对大脑的功能反应进行评估时，改善的时间SNR导致更好的统计功效。在这项研究中，我们证明了cmsEPI与并行成像技术的结合可以为功能成像研究提供更高的功能灵敏度，弥补cmsEPI的较低SNR。
This study was to evaluate the proposed consecutive multishot echo planar imaging (cmsEPI) combined with a parallel imaging technique in terms of signal-to-noise ratio (SNR) and acceleration for a functional imaging study. We developed cmsEPI sequence using both consecutively acquired multishot EPI segments and variable flip angles to minimize the delay between segments and to maximize the SNR, respectively. We also combined cmsEPI with the generalized autocalibrating partially parallel acquisitions (GRAPPA) method. Temporal SNRs were measured at different acceleration factors and number of segments for functional sensitivity evaluation. We also examined the geometric distortions, which inherently occurred in EPI sequence. The practical acceleration factors, R = 2 or R = 3, of the proposed technique improved the temporal SNR by maximally 18% in phantom test and by averagely 8.2% in in vivo experiment, compared to cmsEPI without parallel imaging. The data collection time was decreased in inverse proportion to the acceleration factor as well. The improved temporal SNR resulted in better statistical power when evaluated on the functional response of the brain. In this study, we demonstrated that the combination of cmsEPI with the parallel imaging technique could provide the improved functional sensitivity for functional imaging study, compensating for the lower SNR by cmsEPI.