MRI装置用電磁石の振動磁場解析

抄録

A Magnetic Resonance Imaging (MRI) system is a diagnostic imaging device using magnetic field. In the MRI system, pulse current is energized to gradient coils in a strong static magnetic field generated by a superconducting magnet. Since electromagnetic force (i.e. Lorentz force) is generated in the gradient coils and the superconducting magnet, the MRI magnet system vibrates. Especially, the vibration of MRI system disturbs a homogeneity and stability of the magnetic field. As the magnetic field disturbances causes error magnetic field and affect image quality, it is important to evaluate them in a design process. We are evaluating them by an oscillating magnetic field analysis technology that combines structural analysis and magnetic field analysis. In this study, using excitation forces taking into account operation conditions, the difference of the error magnetic field by the structures of the superconducting magnet was evaluated.