开放式永磁磁共振成像系统中的平板式正交发射线圈的设计  

Design of a flat quadrature RF transmit coil for permanent magnet open MRI systems

作　　者：褚旭[1] 朱晓敏[1] 蒋晓华[1] 

机构地区：[1]清华大学电机工程与应用电子技术系,北京100084

出　　处：《电工电能新技术》2005年第2期32-36,共5页Advanced Technology of Electrical Engineering and Energy

摘　　要：为了提高平板式射频发射线圈的性能,设计了一种正交发射线圈。线圈的结构由优化过程确定,优化目标为产生单位磁场强度所需要的功率,约束条件为成像区域内磁场的均匀度和区域外磁场的快速衰减。为了减小线圈的发射电阻,采用实验方法对导体元件的尺寸和调谐点的分布进行了优化。为了解决单元线圈间的电磁耦合问题,采用了一种π型解耦电路。为一台0 3T磁共振成像系统实际制作了一个发射线圈,并给出解耦电路的调试结果。To improve the efficiency of the flat RF transmit coils, a quadrature coil is designed. The structure is optimized to achieve the best efficiency while the RF magnetic field is kept homogeneous in the imaging volume and drops off quickly outside the imaging volume. To reduce the loss of the coil, some experiments were carried out to determine the cross-section of conductors and the position of the tuning points. A π-type circuit is used to eliminate the electromagnetic coupling between unit coils. A prototype quadrature coil was constructed for a 0.3 T permanent magnet open MRI system, and the experimental results of the decouple circuit are presented.

关 键 词：核磁共振成像 射频线圈 正交线圈 发射线圈 

分 类 号：O482.53[理学—固体物理]