Chronik B A, Rutt B K
Department of Physics and Astronomy, John P. Robarts Research Institute, London, Ontario, Canada.
Magn Reson Med. 1998 Feb;39(2):270-8. doi: 10.1002/mrm.1910390214.
A gradient coil design algorithm capable of controlling the position of the homogeneous region of interest (ROI) with respect to the current-carrying wires is required for many advanced imaging and spectroscopy applications. A modified minimum inductance target field method that allows the placement of a set of constraints on the final current density is presented. This constrained current minimum inductance method is derived in the context of previous target field methods. Complete details are shown and all equations required for implementation of the algorithm are given. The method has been implemented on computer and applied to the design of both a 1:1 aspect ratio (length:diameter) central ROI and a 2:1 aspect ratio edge ROI gradient coil. The 1:1 design demonstrates that a general analytic method can be used to easily obtain very short gradient coil designs for use with specialized magnet systems. The edge gradient design demonstrates that designs that allow imaging of the neck region with a head sized gradient coil can be obtained, as well as other applications requiring edge-of-cylinder regions of uniformity.
许多先进的成像和光谱应用都需要一种梯度线圈设计算法，该算法能够控制感兴趣的均匀区域（ROI）相对于载流导线的位置。本文提出了一种改进的最小电感目标场方法，该方法允许对最终电流密度设置一组约束条件。这种受约束的电流最小电感方法是在先前目标场方法的背景下推导出来的。文中展示了完整的细节，并给出了算法实现所需的所有方程。该方法已在计算机上实现，并应用于设计纵横比为1:1（长度:直径）的中心ROI梯度线圈和纵横比为2:1的边缘ROI梯度线圈。1:1的设计表明，一种通用的解析方法可用于轻松获得适用于特殊磁体系统的非常短的梯度线圈设计。边缘梯度设计表明，可以获得能够使用头部尺寸的梯度线圈对颈部区域进行成像的设计，以及其他需要圆柱边缘区域均匀性的应用。
