AN INTRODUCTION TO NMR IMAGING - FROM THE BLOCH EQUATION TO THE IMAGING EQUATION
AN INTRODUCTION TO NMR IMAGING - FROM THE BLOCH EQUATION TO THE IMAGING EQUATION
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DOI：
10.1109/proc.1983.12592
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发表时间：
1983-01-01
影响因子：
20.6
通讯作者：
LENT, AH
中科院分区：
文献类型：
--
作者：
HINSHAW, WS;LENT, AH
本文介绍了核磁共振成像这一新兴技术在系统识别中的应用。我们展示了如何将选定的信号族输入到系统中（在这种情况下，“系统”几乎与“患者”同义），以便系统对这些输入的响应可以直接用系统参数来解释。一旦识别，系统参数的光栅显示提供了患者的内部图像。系统的输入是时间的四分量函数。一个分量描述射频信号的强度，另外三个分量控制三个空间变化，独立控制的磁场（梯度场）的强度，患者沉浸在其中。作为对这些输入的响应，病人体内的一些质子，按照布洛赫方程的行为，引起磁化的局部波动，这种波动可以用调谐天线和敏感接收器检测到。该输出信号与系统参数之间的关系总结在成像方程中。
The emerging technology of NMR imaging is introduced here as a problem in system identification. We show how selected families of signals may be input into the system ("system," in this case, is almost synonymous with "patient") in order that the system's responses to these inputs may be directly interpreted in terms of the system parameters. Once identified, a raster display of the system parameters provides an internal image of the patient. Inputs to the system age four-component functions of time. One component describes the strength of an RF signal, and the other three components govern the strength of three spatially varying, independently controlled magnetic fields (the gradient fields) in which the patient is immersed. In response to these inputs some of the protons in the patient, acting in concordance with the Bloch equation, give rise to local fluctuations in the magnetization which are detected with a tuned antenna and a sensitive receiver. The relationship between this output signal and the system parameters is summarized in the imaging equation.