Abstract: A magnetic resonance imaging apparatus includes a magnet for generating a static magnetic field, a gradient coil for generating a gradient magnetic field in a measurement space, and a vibration damping means which includes a container and granular material disposed in the container. The vibration damping means is installed with a supporting bolt between the gradient coil and a supporting means. Since the gradient coil is supported at a constant position without any vibration and deformation, the magnetic resonance imaging apparatus generates an accurate image signal without any acoustic noise.

Abstract: A magnetic-resonance imaging apparatus has superconducting magnets for generating a large uniform magnetic field within a predetermined volume. Within that volume, coils for generating magnetic field gradients are supported on a bobbin, enabling an object within the bobbin to be investigated. The coils on the bobbin are subject to forces but are rigidly connected to the bobbin. Therefore, energy is transmitted to the bobbin which can cause the bobbin to vibrate and so generate noise. To dissipate that energy, the coils are attached to tubes, or other hollow members, on the bobbin, which tubes or hollow members contain movable bodies such as particulate material. The energy due to the forces on the coils cause the movable bodies to move and collide, so dissipating the energy and reducing the noise.