A study of sound intensity measurement of MRI driving sound

MRI (Magnetic Resonance Imaging) examination is an important examination in the medical diagnosis. MRI is a technology to image the distribution of inside of body with the nuclear magnetic resonance phenomenon. At this time, noise is generated by using the gradient magnetic field for decision of the imaging position. The noise level is around 100dB though this noise level depends on the imaging method or the resolution parameter. The noise makes subjects of MRI examination revolted, and it makes the ear-protector necessary. It is important to know the noise and to measure the noise for soundproofing. However, it is not clear that the driving sound propagates in MRI examination room. Then, we report the measured result on the sound intensity vector of the driving sound around the gantry of MRI equipment. The analyzed signal was the pulse of the auto-tuning brought by the first stage of imaging operation. The results in the measurement points at 19 points in the boa and 27 points above the table outside the boa were shown. It was shown the MRI driving sound radiated from the gantry side surface, and the vector direction in the boa was a complex result.