Actively shielded gradient coil design for an all-superconducting planar MRI system using progressively-enhanced...

Strong shielding of gradient coils is required to maintain the cryogenic stability of superconducting magnetic resonance imaging (MRI) systems. In planar-type superconducting MRI systems, which extensive use high-conductivity materials, gradient coil sets are embedded within the open slots of the main magnet. In this study, we propose a shielding constraint based on a progressively enhanced shielding coil design method. This approach reduces complexity in coil structure while optimizing gradient coil performance and meeting imaging requirements within the specified diameter of the spherical volume (DSV). We measure the magnetic field distribution at the axial directions and magnetic field distributions produced by the designed gradient coils. Experimental results confirm that the proposed design suppresses stray magnetic fields without excessive coil complexity, while producing highly linear gradient fields in the imaging region.