Spatial encoding with receive coils in MPI

MPI techniques traditionally use gradient magnetic fields for spatial encoding. Despite their proven efficiency, these methods are power-intensive and technically challenging to implement on a human scale. In this work, we explore the potential for spatial encoding of superparamagnetic nanoparticle distributions using only a drive field and an array of receiving coils with unique spatial sensitivity profiles. We demonstrate the feasibility of this concept using a prototype 1D imaging system extended to 2D by mechanically moving the sample. The proposed approach permits high-speed gradient-free data acquisition for rapid imaging but also has some limitations in terms of penetration depth.