Fig. 3

The development history of magnetic particle imaging (MPI) and its applications in brain diseases. After its invention in 2001, Gleich et al. [16] built the first small animal MPI system in 2005. Subsequently, several research groups conducted the exploration of MPI with different shapes [51, 52], and upgraded MPI to multimodal systems, such as MPI-magnetic resonance imaging (MRI) [53] and MPI-computed tomography (CT) systems [54]. Two commercial MPI systems were introduced in 2014 and 2016, subsequently experiencing widespread adoption. At the same time, MPI began to be applied to neuroimaging [33], where its efficacy was investigated across various diseases. With the emergence of human-sized systems [55, 56], the application scenario has been further extended to the simulation of brain diseases in human models [56]. In 2018, the concept of functional magnetic particle imaging (fMPI) was proposed [57], effectively promoting the exploration of MPI in the field of brain function [58, 59]. After 2018, the application of MPI in brain diseases has been expanded, including brain tumors [48, 65, 66], cerebrovascular diseases [60, 61, 64], and neurodegenerative diseases [62]. In 2024, the first human-scale MPI system with superconductor-based selection coils was developed [63]. FFL field-free line, FFP field-free point, CBV cerebral blood volume, SPIONs superparamagnetic iron oxide nanoparticles