Magnetic Particle Imaging: From Tracer Design to Biomedical Applications in Vasculature Abnormality.

Magnetic particle imaging (MPI) is an emerging non-invasive tomographic technique based on the response of magnetic nanoparticles (MNPs) to oscillating drive fields at the center of a static magnetic gradient. In contrast with magnetic resonance imaging (MRI), which is driven by uniform magnetic fields and projects the anatomic information of the subjects, MPI directly tracks and quantifies MNPs in vivo without background signals. Moreover, it does not require radioactive tracers and has no limitations on imaging depth. This review first introduces the basic principles of MPI and important features of MNPs for advanced imaging sensitivity, spatial resolution, and targeted biodistribution. The latest research on optimized MPI tracers is reviewed based on their material composition, physical properties, and surface modifications. Since all the imaging benefits have led to a series of promising biomedical applications, we also discuss recent relational practices of MPI in vascular abnormalities, including cardiovascular and cerebrovascular systems, and cancers. Finally, some considerations of obstructions and recent progress closely related to the clinical translation of MPI are summarized to provide possible direction for future research and development. This article is protected by copyright. All rights reserved.