A Proposal of Gradient Coil Configuration for Low-Field Magnetic Resonance Imaging

The design of gradient coils for low-field permanent magnets faces several challenges. The spatial constraints and eddy currents, concomitant gradient mutual inductances, as well as patient heating are significant challenges to gradient coil design. This study introduces a coil configuration to address these challenges. Particularly, a gradient coil configuration has been developed and studied for portable low-field MRI for the human head. The system consist of the non-local coils for the Y axis gradient and the local cylindrical coils for the X and Z axis gradients. Configuration of the system increases free space within the magnet while enhancing gradient efficiency and linearity. The calculation results of the numerically simulated gradient configuration achieves competitive gradient efficiency and linearity, being able to reduce eddy currents, mutual inductance and heating effects relative to traditional coils. This alternative gradient coil design presents a promising solution for low-field magnetic resonance imaging.