First Nonhuman Primate-Sized Magnetic Particle Imaging System Based on Digital-Scanned Focus Field

Magnetic particle imaging (MPI) is a burgeoning imaging modality that facilitates the reconstruction of position and concentration of superparamagnetic iron oxide nanoparticles. Its potential in clinical applications is substantial, leading to an increasing demand for larger bore sizes in MPI systems. However, the challenge lies in maintaining high resolution, sensitivity, and real-time imaging advantages in larger systems. In this article, we present the design of a 3-D MPI system tailored for nonhuman primates (NHP-MPI) with a bore size of 190 mm. The application of a 3-D digital-scanned focus field is applied to obtain highly sensitive imaging, and the system operates cooling-free under low gradient conditions. In imaging experiments involving a macaque’s brain, our system demonstrated good quantitative performance. The 3-D MPI image yielded satisfactory results for fusion with other structural imaging modalities.