Comparison of velocity-selective arterial spin labeling schemes
Comparison of velocity-selective arterial spin labeling schemes
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DOI：
10.1002/mrm.28572
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发表时间：
2020-10-31
影响因子：
3.3
通讯作者：
Hernandez-Garcia, Luis
中科院分区：
文献类型：
--
作者：
Guo, Jia;Das, Shaurov;Hernandez-Garcia, Luis
在速度选择（VS）动脉自旋标记中，使用多个饱和模块或使用VS反转（VSI）脉冲的策略比使用一个VS饱和（VSS）模块的原始标记方案可以提供更高的信噪比效率。然而，他们的表现改善并没有被直接比较。方法通过Bloch模拟对不同VS标记方案的信噪比效率、涡流灵敏度和对B-1和B-0变化的鲁棒性进行评价。这些方案包括双模双重聚焦双曲正割对称8段b -1不敏感旋转（sBIR8-） VSS脉冲，原始和改进的基于傅里叶变换的VSI脉冲。标记方案的一个子集在幻影和体内实验中进一步检查了它们的涡流灵敏度和信噪比性能。另外一个内置反转的sBIR8-VSS （sBIR8-VSS-inversion）被评估部分背景抑制的效果，以便与VSI进行更公平的比较。结果根据模拟，sBIR8-VSS对场缺陷的鲁棒性最强，与最佳VSI脉冲（sinco -VSI, sinco -VSI）相比，sBIR8-VSS具有同样高的信噪比效率（双模块，双sBIR8-VSS）。这些都被幻影和体内数据所证实。在没有额外背景抑制的情况下，sinci - vsi脉冲的时间信噪比最高，其次是sbir8 - vss反演脉冲，两者都受益于部分背景抑制效应。结论双sbir8 - vss和自- vsi两种VS标记方案的信噪比效率最高。Dual-sBIR8-VSS对场缺陷的抗扰能力最强，而如果能提高对场缺陷的抗扰能力，则可提供更高的信噪比效率。
Purpose In velocity-selective (VS) arterial spin labeling, strategies using multiple saturation modules or using VS inversion (VSI) pulse can provide improved SNR efficiency compared to the original labeling scheme using one VS saturation (VSS) module. Their performance improvement, however, has not been directly compared.Methods Different VS labeling schemes were evaluated by Bloch simulation for their SNR efficiency, eddy current sensitivity, and robustness against B-1 and B-0 variation. These schemes included dual-module double-refocused hyperbolic secant and symmetric 8-segment B-1-insensitive rotation (sBIR8-) VSS pulses, the original and modified Fourier transform-based VSI pulses. A subset of the labeling schemes was examined further in phantom and in vivo experiments for their eddy current sensitivity and SNR performance. An additional sBIR8-VSS with a built-in inversion (sBIR8-VSS-inversion) was evaluated for the effects of partial background suppression to allow a fairer comparison to VSI.Results According to the simulations, the sBIR8-VSS was the most robust against field imperfections and had similarly high SNR efficiency (dual-module, dual-sBIR8-VSS) compared with the best VSI pulse (sinc-modulated, sinc-VSI). These were confirmed by the phantom and in vivo data. Without additional background suppression, the sinc-VSI pulses had the highest temporal SNR, closely followed by the sBIR8-VSS-inversion pulse, both benefited from partial background suppression effects.Conclusion Dual-sBIR8-VSS and sinc-VSI measured the highest SNR efficiency among the VS labeling schemes. Dual-sBIR8-VSS was the most robust against field imperfections, whereas sinc-VSI may provide a higher SNR efficiency if its immunity to field imperfections can be improved.