Study of open-type magnetically shielded room for MRI

The magnetic resonance imaging (MRI) is usually installed in a magnetically shielded room (MSR), in order to reduce the leakage flux density to less than 0.5 mT outside the room. The small space enclosed by the wall causes patients a great deal of stress and discomfort because they are isolated from the operators and from the scenery outside. In order to improve amenity for patients in hospitals, open type of MSRs for MRI, which use canceling coils, combined with square cylinders made by magnetic and conductive material, and magnetic material plates instead of magnetic walls. The magnetic shielding effects of open type of magnetically shielded room combined with square cylinders model made by magnetic, conductive material, magnetic material plates model and lattice shape model made of magnetic material for MRI are estimated by 3-D magnetic field analysis. In this report, we clarified simple lattice of magnetic plate with gap to improve shielding performance using 3D magnetic field analysis. © 2018 The Institute of Electrical Engineers of Japan.