Preliminary Study of Gradient Coils with Variable Gradient Value and Open-Drive Coil in Magnetic Particle Imaging

摘要

Magnetic Particle Imaging (MPI) is a new imaging technology that enables the illustration of SPIO tracer positions with gradient and drive magnetic fields. Currently, the gradient magnetic field of the 1D-MPI system is mainly generated by a permanent magnet. In addition, the gradient value is unchangeable and the size of the detected particles is limited in this way, although it can also create a gradient magnetic field that forms a zero magnetic field point (FFP) in MPI. Moreover, the driving magnetic field is mostly generated in the form of a solenoid. Unfortunately, this approach creates a closed space, which is a pain for claustrophobic patients. In this paper, a new structure is proposed to uses a solenoid to replace the permanent magnet in order to detect more sized particles. The gradient value of the magnetic field can be adjusted with controlling the value of magnetic field of the electromagnetic (EM) coil generated by different current intensity. On the other hand, another open structure coil is designed which can drive FFP in an open test environment instead of the solenoid. The feasibility of the two coil structures proposed in this paper are verified by magnetic field simulation studies.