Multiband accelerated spin-echo echo planar imaging with reduced peak RF power using time-shifted RF pulses.
Multiband accelerated spin-echo echo planar imaging with reduced peak RF power using time-shifted RF pulses.
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DOI：
10.1002/mrm.24719
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发表时间：
2013-05
影响因子：
3.3
通讯作者：
Ugurbil, Kamil
中科院分区：
文献类型：
--
作者：
Auerbach, Edward J.;Xu, Junqian;Yacoub, Essa;Moeller, Steen;Ugurbil, Kamil
旨在评价用于生成多频带RF脉冲的替代方法，该方法用于带切片-GRAPPA解混叠的多频带切片加速成像，在不影响带宽的情况下大幅降低所需的峰值功率。这允许自旋回波方法（例如SE-fMRI和弥散加权MRI）的更高加速度，其中多频带切片加速度受到可用峰值功率的限制。通过在各个频带的RF能量应用之间插入时间偏移来生成多频带“时移”RF脉冲，避免最坏情况下的相长干扰。在3 T下采集体模和人体受试者的切片轮廓和图像。对于典型的sinc脉冲，时移的多频带RF脉冲的产生与单频带脉冲相比，所需的峰值功率增加很少。通过允许更高的脉冲带宽来改善切片轮廓质量，并且通过允许实现最佳翻转角来改善图像质量。已经证明了一种简单的方法，该方法由于多频带RF脉冲的功率要求而显著地简化了对多频带自旋回波成像中可实现的切片加速因子施加的限制。该解决方案将允许在扩散加权MRI应用中增加加速，其中数据采集时间通常非常长，并且加速能力非常有价值。
To evaluate an alternative method for generating multi-banded RF pulses for use in multiband slice-accelerated imaging with slice-GRAPPA unaliasing, substantially reducing the required peak power without bandwidth compromises. This allows much higher accelerations for spin-echo methods such as SE-fMRI and diffusion-weighted MRI where multi-banded slice acceleration has been limited by available peak power. Multi-banded “time-shifted” RF pulses were generated by inserting temporal shifts between the applications of RF energy for individual bands, avoiding worst-case constructive interferences. Slice profiles and images in phantoms and human subjects were acquired at 3T. For typical sinc pulses, time-shifted multi-banded RF pulses were generated with little increase in required peak power compared to single-banded pulses. Slice profile quality was improved by allowing for higher pulse bandwidths, and image quality was improved by allowing for optimum flip angles to be achieved. A simple approach has been demonstrated that significantly alleviates the restrictions imposed on achievable slice acceleration factors in multiband spin-echo imaging due to the power requirements of multi-banded RF pulses. This solution will allow for increased accelerations in diffusion-weighted MRI applications where data acquisition times are normally very long and the ability to accelerate is extremely valuable.
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影响因子：
3.3
作者：
Tuch, DS;Reese, TG;Wedeen, VJ
通讯作者：
Wedeen, VJ
影响因子：
2.5
作者：
Ugurbil, K;Adriany, G;Zhu, XH
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Zhu, XH
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2.2
作者：
CONOLLY, S;NISHIMURA, D;GLOVER, G
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作者：
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作者：
Stables, LA;Kennan, RP;Gore, JC
通讯作者：
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