COIL OPTIMIZATION FOR MRI BY CONJUGATE-GRADIENT DESCENT
COIL OPTIMIZATION FOR MRI BY CONJUGATE-GRADIENT DESCENT
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DOI：
10.1002/mrm.1910210107
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发表时间：
1991-09-01
影响因子：
3.3
通讯作者：
HYDE, JS
中科院分区：
文献类型：
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作者：
WONG, EC;JESMANOWICZ, A;HYDE, JS
提出了一种灵活的迭代算法，用于优化MRI梯度和射频线圈。它是基于一个模型，使用离散电流元素和直接毕奥-萨伐尔计算的领域。在感兴趣区域（ROI）上定义误差函数，并通过共轭梯度下降使其最小化。误差函数的选择允许以任何组合优化线圈的场均匀性、电感和效率。线圈和ROI都不限于任何特定的几何形状。针对半径为0.7a、长度为2a的ROI设计的半径为a、长度为4a的40匝圆柱形z梯度线圈，在生成的梯度场中的平均误差为0.85%，电感为0.014amH/cm，效率为6.65a−2Gem/A。半径为5 cm的16匝鸟笼状RF线圈，设计用于半径为4 cm的ROI，平均误差为0.79%。出版社：Academic Press，Inc.
A flexible iterative algorithm is presented for optimizing gradient and radio frequency coils for MRI. It is based on a model using discrete current elements and direct Biot‐Savart calculation of the fields. An error function is defined over a region of interest (ROI) and is minimized by conjugate gradient descent. The choice of error function allows optimization of the field uniformity, the inductance, and the efficiency of the coil in any combination. Neither the coil nor the ROI is restricted to any particular geometry. A 40‐ turn cylindrical z‐gradient coil of radiusaand length 4a, designed for a ROI of radius 0.7aand length 2ahas an average error in the gradient fields generated of 0.85%, an inductance of 0.014amH/cm, and an efficiency of 6.65a−2Gem/A. A 16‐turn birdcage‐like RF coil of radius 5 cm, designed for a ROI of radius 4 cm has an average error of 0.79%. © 1991 Academic Press, Inc.