Increased SNR efficiency in velocity selective arterial spin labeling using multiple velocity selective saturation modules (mm-VSASL)
Increased SNR efficiency in velocity selective arterial spin labeling using multiple velocity selective saturation modules (mm-VSASL)
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DOI：
10.1002/mrm.25462
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发表时间：
2015-09-01
影响因子：
3.3
通讯作者：
Wong, Eric C.
中科院分区：
文献类型：
--
作者：
Guo, Jia;Wong, Eric C.
目的速度选择性动脉自旋标记（VSASL）理论上对传输延迟（TD）不敏感。然而，它使用饱和而不是反转，导致折衷的信噪比（SNR）。在这项研究中，我们探讨使用多个速度选择性饱和（VSS）模块在VSASL（mm-VSASL），以提高SNR.MethodsTheoretical SNR效率的改善和优化参数计算模拟mm-VSASL。采用VSASL（VSASL-2 VSS）测量活体脑血流量，并与常规VSASL（VSASL-1VSS）、脉冲ASL（PASL）和伪连续ASL（PCASL）进行比较。TD和团注持续时间（BD）进行了测量，以验证模拟和检查TD的灵敏度，这些preparation.ResultsCompared VSASL-1VSS，VSASL-2 VSS实现了显着改善的SNR（22.1 ± 1.9%，P = 1.7 × 10（-6））在体内，符合从模拟预测的22.7%的改善。SNR与使用PCASL的SNR相当或更高（在灰质中，P = 4.3 x 10（-3））。实验验证VSASL具有最小的TD effects. ConclusionUsing多VSS模块可以提高VSASL的SNR效率。Mm-VSASL可以导致SNR，相当于或甚至高于PCASL在应用中，需要长的postlabeling延迟。Magn Reson Med 74：694-705，2015. (c)2014 Wiley Periodicals，Inc.
PurposeVelocity-selective arterial spin labeling (VSASL) is theoretically insensitive to transit delay (TD) effects. However, it uses saturation instead of inversion, resulting in compromised signal to noise ratio (SNR). In this study we explore the use of multiple velocity-selective saturation (VSS) modules in VSASL (mm-VSASL) to improve SNR.MethodsTheoretical SNR efficiency improvement and optimized parameters were calculated from simulations for mm-VSASL. VSASL with two VSS modules (VSASL-2VSS) was implemented to measure cerebral blood flow in vivo, compared with conventional VSASL (VSASL-1VSS), pulsed ASL (PASL), and pseudo-continuous ASL (PCASL). TDs and bolus durations (BDs) were measured to validate the simulations and to examine the TD sensitivity of these preparations.ResultsCompared with VSASL-1VSS, VSASL-2VSS achieved a significant improvement of SNR (22.1 1.9%, P = 1.7 x 10(-6)) in vivo, consistent with a 22.7% improvement predicted from simulations. The SNR was comparable to or higher (in gray matter, P = 4.3 x 10(-3)) than that using PCASL. VSASL was experimentally verified to have minimal TD effects.ConclusionUtilizing multiple VSS modules can improve the SNR efficiency of VSASL. Mm-VSASL may result in an SNR that is comparable to or even higher than that of PCASL in applications where long postlabeling delays are required. Magn Reson Med 74:694-705, 2015. (c) 2014 Wiley Periodicals, Inc.