Abstract: Iron oxide nanoparticles (IONPs) are investigated because of their chemical tunability and potential as diagnostic and therapeutic agents. In magnetic particle imaging (MPI), an emerging imaging modality that enables the direct mapping of IONP tracers, the signal generation relies heavily on the magnetization reversal of the IONP tracers. As such, it is essential to tune the IONP’s magnetic properties to achieve good MPI image resolution. To date, most studies have focused in optimizing spherical magnetite IONPs in MPI applications. In this presentation, a systematic investigation of the effects of chemical doping and shape anisotropy on the MPI performance of IONP tracers will be discussed. Moreover, the demonstration of focused hyperthermia through an MPI-guided approach will be presented.