用于小口径5 T磁共振成像系统的梯度线圈和^(1)H/^(13)C双共振射频线圈研制

Development of Gradient Coils and^(1)H/^(13)C Dual-resonance RF Coils for a Small-bore 5 T MRI System

基于自主研制的5 T磁共振成像系统和^(13)C代谢磁共振成像研究需求,设计了一种小口径磁共振成像梯度线圈和^(1)H/^(13)C双共振射频线圈系统.其中梯度线圈设计采用有限差分流函数方法,射频线圈设计为马鞍线圈结合表面线圈的双共振方案.采用有限元方法对磁场分布进行了数值模拟分析,成功研制出一套用于小口径5 T^(13)C磁共振成像的梯度与射频线圈,并利用自主研制的5 T磁共振成像系统平台验证了设计方案的可行性,经过实验测试采集到^(13)C标记的尿素水模磁共振图像和小鼠头部^(1)H磁共振图像,为后续开展基于动态核极化的^(13)C磁共振代谢成像奠定了基础.

Based on the independently developed 5 T magnetic resonance imaging(MRI)system and research needs of^(13)C metabolic MRI,a gradient coil and^(1)H/^(13)C dual resonance radiofrequency(RF)coil system for small-bore MRI were designed.The gradient coil was designed by using the finite-difference stream function method,and the RF coil was designed as a saddle coil combined with a surface coil in a dual-resonance scheme.Numerical simulation analysis of the magnetic field distribution was carried out by using the finite-element method,and a set of gradient and RF coils for small-bore 5 T^(13)C MRI was successfully developed.The feasibility of the design scheme was verified using a home-made 5 T MRI system,and the magnetic resonance images of^(13)C-labeled urea phantom and^(1)H magnetic resonance images of mice head were acquired by experimental tests,which lays a foundation for^(13)C metabolic MRI based on dynamic nuclear polarization in the future.