Shim design using a linear programming algorithm
Shim design using a linear programming algorithm
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DOI：
10.1002/mrm.20176
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发表时间：
2004-09
影响因子：
3.3
通讯作者：
S. E. Ungersma;Hao Xu;B. Chronik;G. Scott;A. Macovski;S. Conolly
中科院分区：
文献类型：
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作者：
S. E. Ungersma;Hao Xu;B. Chronik;G. Scott;A. Macovski;S. Conolly
开放式磁共振成像（MRI）扫描仪和针对特定身体部位定制的专用MRI扫描仪的出现导致非圆柱形MRI扫描仪几何形状的数量不断增加，为此需要非圆柱形梯度和梯度。这些新的扫描器几何形状推动了对快速、灵活的匀场设计方法的需求，这些方法可以为任何几何形状设计匀场线圈。开发了一种线性规划（LP）算法，用于在任意表面上设计最小功率电阻匀场线圈。这些线圈可以被设计为在任意形状的目标区域上产生任何阶次的匀场，该目标区域可以被放置在线圈内的任何地方。由此产生的设计是相对稀疏的，可以很容易地构建。该算法用于设计和构建具有圆柱形均匀区域的膝关节成像磁体的七线圈圆柱形垫片组。然后，该算法被用来设计匀场线圈的双径向头部成像与非对称定位的球形目标区域的脑成像。Magn Reson Med 52：619 - 627，2004.© 2004 Wiley利斯公司
The advent of open magnetic resonance imaging (MRI) scanners and dedicated MRI scanners tailored to specific body parts has led to an increasing number of noncylindrical MRI scanner geometries, for which noncylindrical gradients and shims are needed. These new scanner geometries are driving the need for fast, flexible shim design methods that can design shim coils for any geometry. A linear programming (LP) algorithm was developed to design minimum‐power resistive shim coils on an arbitrary surface. These coils can be designed to produce any order shim field over an arbitrarily shaped target region, which can be placed anywhere within the coil. The resulting designs are relatively sparse and can be readily constructed. This algorithm was used to design and construct a seven‐coil cylindrical shim set for a knee imaging magnet with a cylindrical homogeneous region. The algorithm was then used to design shim coils for a biradial head imager with an asymmetrically located spherical target region for brain imaging. Magn Reson Med 52:619–627, 2004. © 2004 Wiley‐Liss, Inc.