Boyer J S, Wright S M, Porter J R
Department of Electrical Engineering, Texas A & M University, College Station 77843-3128, USA.
J Magn Reson Imaging. 1998 May-Jun;8(3):740-7. doi: 10.1002/jmri.1880080334.
A fully automated laboratory-based measurement system for characterization of coil system parameters is presented. This method uses an inexpensive personal computer (PC)-controlled stepper motor positioning system in conjunction with a network/spectrum analyzer and an analog-to-digital converter (A/D) board that allows high resolution data acquisition in an unattended manner. A graphical interface was created for complete control of stepper motor movement, measurement, and data acquisition. The system is capable of performing a wide range of measurements that can, either individually or combined, characterize radiofrequency (RF) and gradient coils used in MRI. Measurement methods, theory, and results for conductor and shield current distributions, mutual impedance, and magnetic fields are given. Comparisons with theoretical calculations are included to validate the accuracy and utility of the system.
本文介绍了一种用于表征线圈系统参数的全自动化实验室测量系统。该方法使用了一个由廉价个人计算机（PC）控制的步进电机定位系统，结合网络/频谱分析仪和模数转换器（A/D）板，可实现无人值守的高分辨率数据采集。创建了一个图形界面，用于完全控制步进电机的运动、测量和数据采集。该系统能够执行广泛的测量，这些测量单独或组合起来，可以表征磁共振成像（MRI）中使用的射频（RF）线圈和梯度线圈。给出了导体和屏蔽电流分布、互阻抗和磁场的测量方法、理论和结果。还包括与理论计算的比较，以验证系统的准确性和实用性。
