Simulation of a single-sided MPI handheld device with offset magnetic field for spatial encoding

Abstract

Single-sided MPI devices provide images from regions outside of an enclosed scanner but they are constrained by limited in detection depth and non-uniform magnetic field distribution, which restrict imaging quality and sensitivity. In this study, we propose a novel handheld single-sided MPI device that utilizes an offset magnetic field with varying amplitude, coupled with high-frequency dynamic magnetic fields, to excite magnetic nanoparticles and sensitively capture the harmonic variations in spatial distribution. By moving the device horizontally in a direction perpendicular to the depth, two-dimensional spatial distribution information of magnetic nanoparticles can be acquired without the need for classical static selection fields. When the depth distance is 0-15 mm, the best spatial resolution is 1 mm. This technology holds the promise of achieving real-time imaging of superficial human tissue layers with lower cost and a simpler device structure.