Magnetic particle imaging is a tomographic imaging modality and research field focused on the direct detection and quantification of superparamagnetic iron oxide nanoparticles (SPIOs) within a subject. It operates by exploiting the non-linear magnetization response of SPIOs to applied oscillating magnetic fields, enabling the reconstruction of their spatial distribution with high sensitivity, specificity, and without the use of ionizing radiation, making it significant for potential diagnostic and therapeutic applications.