Examination of the Shielding Performance of the Open-Type Magnetic Shield for MRI by Shielding Shape

Abstract

MRI diagnoses various diseases by using a very strong magnetic field. In order to prevent electronic equipment malfunction caused by this magnetic field, the International Non-ionizing Radiation Protection Committee regulates access around the MRI laboratory, MSR (Magnetically Shielded Room) is used for shielding the magnetic field. Since the conventional MSR for MRI has a shape that the upper, lower, and side surface are hermetically sealed with shields, it gives closure to patients. Recently, open-type MSRs have been researched which have openings on the side, which can take in outside light and scenery into the MSR and can see the state of examination from the outside. However, open-type MSR has a problem that the volume increases from the shape of the shield at the opening. In this research, in order to propose an open type MSR with a volume equal to or close to that of the conventional model, we analyzed the shield cross sectional area and gap width as a parameter. Three-dimensional static magnetic field analysis using finite element method was used.