System function analysis of MPI with Field-Free Line and excitation coil configurations

Magnetic Particle Imaging (MPI) visualizes the distribution of magnetic particles using their nonlinear magnetization response. This study evaluated the impact of interference between the Field-Free Line (FFL) and alternating excitation field on system performance. The Coaxial Configuration suppressed interference and provided stable in-phase signals, while the Orthogonal Configuration produced anti-phase signals, reducing sensitivity. The Coaxial Configuration is suitable for wide-area measurements, whereas the Orthogonal Configuration offers high resolution but faces sensitivity challenges.