| Keywords |
MRI room ; Operating noise ; A-weighted sound level ; Noise rating curves |
| Abstract |
Magnetic resonance imaging (MRI) in modern medical science is a method of imaging by putting a person into a device generating a magnetic field to generate high frequency and analyze the signals generated from inside the body. However, MRI causes serious noises while coils move within the device to generate a strong magnetic field. These noises can give serious physical and psychological distress to patients. For this reason, various data are needed to reduce the noises generated from MRI operation; however, South Korea has had almost no relevant research. From this perspective, this study selected four MRI devices with different degrees of a magnetic field, measured noises for each source of MRI operation, and analyzed the waveform, the sound pressure level based on frequency, and the weighted sound level or dB(A). On the basis of these data, MRI operation noises were evaluated with dB(A) and NR to determine how much they affected patients. The MRI operation noises could be divided into four waveforms and most of them were extremely high in the medium-to-high frequency bands, with the exception of the WN noises. When the MRI operation noises were evaluated with dB(A), the NR curve, and PSIL, 0.3T of the magnetic field led to 57.1-64 dB(A), NR 53-62, and 1.98-3.96 m for medium sound, and 4.26-8.31 m for loud sound, with no significant effect on patients. In contrast, 1-3T of the magnetic field led to 74.4-90.9 dB(A) and NR 72-89 for Noise T1, 85.9-91.7 dB(A) and NR 83-90 for Noise T2, 90.5-28.1 dB(A) and NR 87-98 for Noise D, 79.4-89.8 dB(A) and NR 77-89 for Noise G, 0.06-0.65 m for medium sound, and 0.12-1.29 m for loud sound in terms of PSIL. Because of patients' exposure to very serious noises, it is urgent to take measurements then. In particular, 1-3T of the magnetic field, which can affect patients, led to 100-1,000 Hz of grading frequency for the NR curve; therefore, it is essential to lower the noise level of this band with the objective of reducing damages from the exposure to serious noises during an MRI scan. |