基于射频场测量的去耦技术在磁共振相控阵线圈中的应用

目的将基于射频场测量的去耦技术应用于核磁共振相控阵线圈以消除核磁共振图像由于阵列单元之间耦合引起的伪影.方法利用测量得到的单个线圈和阵列单元的射频场计算阵列中各个单元之间的耦合系数矩阵以及相应的去耦系数矩阵,并将后者作用于阵列中各单元线圈射频场,以消除各个单元之间的耦合.结果此方法用基于有限元的高频结构仿真软件HFSS进行了仿真,并对仿真结果用计算机模拟核磁共振图像进行了验证, 两者之间具有很好的一致性.结论证明该方法有效驱除了阵列单元之间的耦合效应.

Decoupling theory based on radio frequency field mappingand its application to MRI phased array coil

Objective A new decoupling technique based on radio frequency field (B1 field) mapping for phased array coil in magnetic resonance imaging (MRI) was presented to eliminate image artifact arising from interaction between element coils in an array. Methods Coupling matrix and its corresponding decoupling matrix were calculated from B1 field map of single coil and element coils in an array. Element coils in the array were decoupled by multiplying decoupling matrix with B1 field map of each element in the array. Results This method was verified by high frequency structure simulation software HFSS and compared with the simulation in the cases with and without coupling artifact collection for MRI. The results showed that the consistent was well established. Conclusion The coupling between element coils in an array was eliminated effectively by this method.