Development of Small-Rabbit-Scale Three-Dimensional Magnetic Particle Imaging System With Amplitude-Modulation-Based Reconstruction

Magnetic particle imaging (MPI) is an emerging noninvasive molecular imaging method that can image the concentration and position of superparamagnetic iron oxide nanoparticles. Its applications in the biomedical field are increasing rapidly. However, the scalability of MPI is the major barrier to its clinical use at the moment. For a large bore size of MPI, it is important to achieve a high magnetic gradient for high image resolution with a large field-of-view (FOV) while allowing fast scanning and high sensitivity. In this article, we present a small-rabbit-scale three-dimensional (3-D) amplitude modulation (AM) MPI system with a bore size of 90 mm and a high magnetic gradient of up to 4 T/m/μ0. The AM MPI with a soft core can allow a large FOV and good resolution while minimizing the peripheral nerve stimulation constraint and hardware requirements. This new design guideline and optimum design parameters of 3-D AM MPI for scalability were suggested and verified by simulation and experimental studies to allow fast scanning with high resolution and high sensitivity while avoiding vibration and heating issues.