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

Based on the independently developed 5 T magnetic resonance imaging (MRI) system and research needs of 13C metabolic MRI, a gradient coil and 1H/13C 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 13C 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 13C-labeled urea phantom and 1H magnetic resonance images of mice head were acquired by experimental tests, which lays a foundation for 13C metabolic MRI based on dynamic nuclear polarization in the future.