An orthogonal shim coil for 3T brain imaging.
An orthogonal shim coil for 3T brain imaging.
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用于 3T 脑成像的正交匀场线圈。
DOI：
10.1002/mrm.28010
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发表时间：
2020
影响因子：
3.3
通讯作者：
Lin,Fa-Hsuan
中科院分区：
文献类型：
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作者：
Zhou,Jiazheng;Stockmann,JasonP;Arango,Nicolas;Witzel,Thomas;Scheffler,Klaus;Wald,LawrenceL;Lin,Fa-Hsuan
目的设计并实现了一种由匀场线圈组成的正交匀场阵列，匀场线圈的平面垂直于相邻射频线圈的平面。该匀场线圈通过最大限度地减少对RF coils.MethodsUsing人类大脑的现实非共振地图来提高磁场均匀性，我们首先评估了不同方向的匀场线圈的性能。基于模拟，我们开发了一个7通道正交匀场阵列，其线圈平面垂直于前额的相邻RF线圈。一个可编程的开源电流驱动器提供shim current.ResultsThe 7通道正交匀场阵列只造成边际SNR损失的集成32通道RF匀场阵列。7通道正交匀场阵列本身在切片优化匀场中将磁场均匀性提高了30%，与扫描仪的二阶球谐匀场提供的基线匀场相当。ConclusionOrthogonal匀场线圈可以提高磁场均匀性，同时保持高图像SNR。
PurposeWe designed and implemented an orthogonal shim array consisting of shim coils with their planes perpendicular to the planes of neighboring RF coils. This shim coil improves the magnetic field homogeneity by minimizing the interference to RF coils.MethodsUsing realistic off‐resonance maps of the human brain, we first evaluated the performance of shim coils in different orientations. Based on simulations, we developed a 7‐channel orthogonal shim array, whose coil plan was perpendicular to neighboring RF coils, at the forehead. A programmable open‐source current driver supplied shim currents.ResultsThe 7‐channel orthogonal shim array caused only marginal SNR loss to the integrated 32‐channel RF‐shim array. The 7‐channel orthogonal shim array itself improved the magnetic field homogeneity by 30% in slice‐optimized shimming, comparable to the baseline shimming offered by the scanner’s 2nd order spherical harmonic shimming.ConclusionOrthogonal shim coils can improve the field homogeneity while maintaining high image SNR.