A number of clinical applications for MRI have been developed in accordance with the advancement in imaging technology. Recently, medical checkup of brain or heart are becoming popular. In this situation, there is a growing need for performance improvement of MRI and thus acoustic noise during examinations tends to become louder with the use of higher static magnetic field and higher gradient performance. Noise reduction measures for MRI are classified into two categories, pulse sequence optimization and hardware renovation. For pulse sequence, noise is reduced by decreasing the changes of the current applied for gradient coil. Since there exist solid-borne sound and airborne sound, for hardware measure, not only making gradient coil itself vibration suppressed structure but also controlling vibration to prevent propagation of sounds to the other structure is required. PianissimoTM mechanism employs both solid-borne sound suppression and airborne sound suppression by vacuum-encapsulating the gradient coil, and realizes 33 dB noise reduction. PianissimoTM mechanism, in contrast to the noise reduction by pulse sequence modification, reduces the acoustic noise produced by scans of all kinds and can be readily adapted to the newly developed applications regardless of imaging technique.
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