Quiet magnetic resonance imaging apparatus

摘要

A gradient magnetic field generation apparatus for generating a gradient magnetic field in a space in which an inspection object is placed includes at least one gradient magnetic field coil and a retaining member of the coil which undergoes deformation vibration by an electromagnetic force generated when a current is caused to flow through the coil. This apparatus generates noise and vibration whenever a pulse current is applied to the coil, because an electromagnetic force develops in the coil due to the pulse current and the coil as well as the retaining member of the coil undergo deformation and vibration. Therefore, a force which inhibits this deformation and vibration is applied to the retaining member so as to prevent deformation and vibration of the coil and the retaining member and to keep their shapes constant. In a preferred embodiment, a piezoelectric device is fixed to the retaining member without damping, and the force for inhibiting deformation and vibration of the retaining member is applied by controlling a voltage applied to the piezoelectric device.