An insertable nonlinear gradient coil for phase compensation in SEA imaging.
An insertable nonlinear gradient coil for phase compensation in SEA imaging.
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用于 SEA 成像中相位补偿的可插入非线性梯度线圈。
DOI：
10.1109/tbme.2013.2238537
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Wright,StevenM
中科院分区：
文献类型：
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作者：
Bosshard,JohnC;McDougall,MaryPreston;Wright,StevenM
在具有多个元件的阵列线圈的磁共振成像中，当射频(RF)线圈的尺寸接近体素尺寸时，由线圈的磁场模式引起的相位梯度导致每个体素内的信号抵消。在采用线圈阵列的单次回波捕获(SEA)成像中，可以应用梯度脉冲来补偿这种影响。然而，由于射频线圈的相位随距阵列的距离而变化，并且在双面阵列的相反侧上反转，因此这种相位补偿方法一次只能针对单个切片进行优化。在这项研究中，实现了一个非线性梯度线圈，以提供空间变化的相位补偿，以补偿双面窄线圈阵列的线圈相位与切片位置。这种非线性梯度线圈允许使用一个相位补偿脉冲来对穿过平板的多个切片成像，并且重要的是，所示的能够使用双面接收阵列从样品的相反侧同时进行海洋成像。
In magnetic resonance imaging with array coils with many elements, as the radiofrequency (RF) coil dimensions approach the voxel dimensions, the phase gradient due to the magnetic field pattern of the coil causes signal cancellation within each voxel. In single echo acquisition (SEA) imaging with coil arrays, a gradient pulse can be applied to compensate for this effect. However, because RF coil phase varies with distance from the array and reverses on opposite sides of a dual-sided array, this method of phase compensation can be optimized for only a single slice at a time. In this study, a nonlinear gradient coil was implemented to provide spatially varying phase compensation to offset the coil phase with slice position for dual-sided arrays of narrow coils. This nonlinear gradient coil allows the use of one phase compensation pulse for imaging multiple slices through a slab, and, importantly, is shown to enable simultaneous SEA imaging from opposite sides of a sample using a dual-sided receive array.