Single-harmonic-based narrowband MPI: Effect of different harmonics

Single-harmonic-based narrowband magnetic particle imaging (MPI) is one of the most promising approaches, which only measures a single harmonic to visualize the spatial distribution of superparamagnetic iron oxide nanoparticles (SPIONs). In this paper, we investigate the effect of different harmonics, e.g. the 3^{r d}, the 5^{t h} and the 7^{t h} harmonic, on the spatial resolution of single-harmonic-based narrowband MPI. The point spread functions of different harmonics at an excitation magnetic field of 4 mT and 10 kHz are simulated and evaluated by comparing the full width at half maximum (FWHM). The 3^{r d}, the 5^{t h}, and the 7^{t h} harmonics are used to reconstruct MPI images to investigate their effects on the spatial resolution. Simulation results indicates that with increasing harmonic order, the FWHM get narrower and the spatial resolution gets improved.