Gradient characterization using a Fourier-transform technique
Gradient characterization using a Fourier-transform technique
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DOI：
10.1002/mrm.1910390411
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发表时间：
1998-04-01
影响因子：
3.3
通讯作者：
Pelc, NJ
中科院分区：
文献类型：
--
作者：
Alley, MT;Glover, GH;Pelc, NJ
本文描述了一种表征磁共振系统梯度子系统的技术。该技术使用傅里叶变换分析来直接测量由任意梯度波形产生的k空间轨迹。此外，该方法可以很容易地扩展到多个维度，并且可以适应于测量涡流等残余梯度效应。给出了梯度波形和涡流测量的几个例子。此外，还演示了如何使用脉冲响应形式将涡流测量参数化，以便以后在系统调谐中使用。与峰拟合分析相比，该技术提供了更直接的k空间测量提取，从而减少了分析误差的可能性。与传统的涡流测量技术相比，这种方法也有几个优点，包括能够测量非常短的时间常数效应。
This paper describes a technique for characterizing the gradient subsystem of a magnetic resonance, (MR) system. The technique uses a Fourier-transform analysis to directly measure the k-space trajectory produced by an arbitrary gradient waveform. In addition, the method can be easily extended to multiple dimensions and can be adapted to measuring residual gradient effects such as eddy currents. Several examples of gradient waveform and eddy-current measurements are presented. Also, it is demonstrated how the eddy-current measurements can be parameterized with an impulse-response formalism for later use in system tuning. When compared to a peak-fitting analysis, this technique provides a more direct extraction of the k-space measurements, which reduces the possibility of analysis error. This approach also has several advantages as compared to the conventional eddy-current measurement technique, including the ability to measure very short time constant effects.