The Role of Nonlinear Gradients in Parallel Imaging: A k-Space Based Analysis.
The Role of Nonlinear Gradients in Parallel Imaging: A k-Space Based Analysis.
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DOI：
10.1002/cmr.a.21243
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
Constable RT
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文献类型：
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作者：
Galiana G;Stockmann JP;Tam L;Peters D;Tagare H;Constable RT
使用非线性梯度场对对象的空间信息进行编码的序列是MRI中的新前沿，具有提供较低的外周神经刺激、窗口视野、定制的空间变化分辨率、反映生理几何形状的弯曲切片以及最重要的是，使用多通道线圈的非常快速的并行成像的潜力。多通道图像的加速通常由曲线梯度等值线更好地补充由典型接收器阵列提供的方位角空间编码的事实来解释。然而，这种互补性的细节更难以具体说明。我们提出了一个简单而直观的框架来描述图像形成的力学与非线性梯度，我们用这个框架来审查一些主要类别的非线性编码方案。
Sequences that encode the spatial information of an object using nonlinear gradient fields are a new frontier in MRI, with potential to provide lower peripheral nerve stimulation, windowed fields of view, tailored spatially-varying resolution, curved slices that mirror physiological geometry, and, most importantly, very fast parallel imaging with multichannel coils. The acceleration for multichannel images is generally explained by the fact that curvilinear gradient isocontours better complement the azimuthal spatial encoding provided by typical receiver arrays. However, the details of this complementarity have been more difficult to specify. We present a simple and intuitive framework for describing the mechanics of image formation with nonlinear gradients, and we use this framework to review some the main classes of nonlinear encoding schemes.