Three-Dimensional GRE T1ρ mapping of the brain using tailored variable flip-angle scheduling
Three-Dimensional GRE T1ρ mapping of the brain using tailored variable flip-angle scheduling
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DOI：
10.1002/mrm.28198
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发表时间：
2020-02-12
影响因子：
3.3
通讯作者：
Magnotta, Vincent A.
中科院分区：
文献类型：
--
作者：
Johnson, Casey P.;Thedens, Daniel R.;Magnotta, Vincent A.
目的介绍一种新的方法，称为定制的可变翻转角（VFA）调度，用于使用磁化准备的梯度回波序列进行SNR有效的脑3D T-1 rho标测。方法使用模拟来评估相对SNR效率，定量准确性，和空间模糊的定制VFA调度的T-1 rho映射的脑组织相比，磁化准备的角度调制分区k-空间扰相梯度回波快照（MAPSS），一种用于精确3D梯度回波T-1 ρ标测的最先进技术。模拟也被用来计算最佳成像参数的定制VFA调度与MAPSS，没有和有空的CSF。四名参与者在3 T MRI上成像，以证明定制VFA计划用于大脑T-1 rho映射的可行性。使用MAPSS作为参考标准，结果当使用相同的序列参数时，与MAPSS相比，定制的VFA调度可以提供所得T-1 rho图的SNR的2倍至4倍增益，同时将T-1 rho定量误差限制在2%或更小。1 rho地图收购量身定制的VFA调度有上级SNR效率比MAPSS实现，和SNR效率提高了更多的意见，每segment.Conclusions定制的VFA调度是一个SNR有效的GRE技术的3D T-1 rho映射的大脑，提供了更大的灵活性，在选择成像参数相比，MAPSS，这可能有利于各种应用。
Purpose To introduce a new approach called tailored variable flip-angle (VFA) scheduling for SNR-efficient 3D T-1 rho mapping of the brain using a magnetization-prepared gradient-echo sequence.Methods Simulations were used to assess the relative SNR efficiency, quantitative accuracy, and spatial blurring of tailored VFA scheduling for T-1 rho mapping of brain tissue compared with magnetization-prepared angle-modulated partitioned k-space spoiled gradient-echo snapshots (MAPSS), a state-of-the-art technique for accurate 3D gradient-echo T-1 rho mapping. Simulations were also used to calculate optimal imaging parameters for tailored VFA scheduling versus MAPSS, without and with nulling of CSF. Four participants were imaged at 3T MRI to demonstrate the feasibility of tailored VFA scheduling for T-1 rho mapping of the brain. Using MAPSS as a reference standard, in vivo data were used to validate the relative SNR efficiency and quantitative accuracy of the new approach.Results Tailored VFA scheduling can provide a 2-fold to 4-fold gain in the SNR of the resulting T-1 rho map as compared with MAPSS when using identical sequence parameters while limiting T-1 rho quantification errors to 2% or less. In vivo whole-brain 3D T-1 rho maps acquired with tailored VFA scheduling had superior SNR efficiency than is achievable with MAPSS, and the SNR efficiency improved with a greater number of views per segment.Conclusions Tailored VFA scheduling is an SNR-efficient GRE technique for 3D T-1 rho mapping of the brain that provides increased flexibility in choice of imaging parameters compared with MAPSS, which may benefit a variety of applications.