Spatial selectivity enhancement in RF-hyperthermia by magnetic flux confinement

Abstract

Aiming to increase spatial selectivity which provides the precision in hyperthermia therapy and high resolution in imaging, we propose a strategy to increase field gradient for Magnetic Particle Imaging (MPI) modality. In this study, a solution for an existing MPI system topology was simulated, which uses additional soft magnetic material as iron core retrofit at the center of selection field coil. Due to core property of high magnetic permeability relative to air, magnetic flux gets confined to increase selection field gradient field slope. Within this simulation study, the optimal core position is evaluated whilst its effects on the magnet system is validated. We found that this technique increases the magnetic field gradient up to a factor of 1.4 from 2.5 T/m to 3.4 T/m in z-direction, without significant loading of the drive field resonance circuit due to power losses caused by eddy currents in the MPI compatible iron core shielding.

Int. J. Mag. Part. Imag. 6(2), Suppl. 1, 2020, Article ID: 2009015, DOI: 10.18416/IJMPI.2020.2009015