An analytic framework for the evaluation of coil configurations for parallel transmission MRI with subsampled cartesian excitation k-space.
An analytic framework for the evaluation of coil configurations for parallel transmission MRI with subsampled cartesian excitation k-space.
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用于评估具有子采样笛卡尔激励 k 空间的并行传输 MRI 线圈配置的分析框架。
DOI：
10.1109/tmi.2009.2037496
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发表时间：
2010
影响因子：
10.6
通讯作者：
Morrell,GlenR
中科院分区：
文献类型：
--
作者：
Morrell,GlenR
使用多个独立的同时射频（RF）发射器和线圈，称为并行传输，有可能使多维激励适用于广泛的磁共振成像应用。并行传输系统中RF线圈的灵敏度分布决定了系统的性能。我们提出了一个理论框架，允许并行传输的线圈阵列的性能的评估。我们通过理论分析和蒙特卡罗模拟表明，所提出的框架预测的保真度的激励，可以实现由一个给定的线圈配置中存在的噪声中测量的线圈灵敏度配置文件。我们评估了四个候选线圈配置的四通道并行传输系统与嘈杂的线圈灵敏度估计实现的激励保真度。理论结果得到了Monte Carlo模拟的证实。研究结果为并行传输线圈结构的设计提供了参考。特别地，对于子采样的笛卡尔激励k空间的激励的最佳保真度通过具有均匀幅度和每个通道的增加的线性相位的线圈灵敏度分布来实现。这样的灵敏度分布可以用扭曲的鸟笼线圈设计来实现。
The use of multiple independent simultaneous radio-frequency (RF) transmitters and coils, known as parallel transmission, has the potential to make multidimensional excitation applicable to a wide range of magnetic resonance imaging applications. The sensitivity profile of the RF coils in a parallel transmission system determines the performance of the system. We present a theoretical framework, allowing the evaluation of the performance of a coil array for parallel transmission. We show through theoretical analysis and Monte Carlo simulation that the proposed framework predicts the fidelity of excitation that can be achieved by a given coil configuration in the presence of noise in the measured coil sensitivity profiles. We evaluate the fidelity of excitation achieved by four candidate coil configurations for a four-channel parallel transmission system with noisy coil sensitivity estimates. Theoretical results are confirmed with Monte Carlo simulation. The results give insight into the design of coil configurations for parallel transmission. In particular, optimal fidelity of excitation for subsampled Cartesian excitationk-space is achieved with a coil sensitivity profile having uniform amplitude and increasing linear phase for each channel. Such sensitivity profiles may be achieved with twisted birdcage coil designs.