Evaluation of Effective Sound Insulation Method for Noise Generated by MRI

Background/Objectives: MRI is a popular method in modern diagnostic medicine. However, MRI equipment produces 65 to 130 kHz noise when operated, which can cause patients to feel anxious or fear enclosed spaces. To lower the level of noise, method such as earplugs and headsets have been used.

Method/Statistical Analysis: In this study, the researchers tried to find out the effective sound insulation method by measuring the degree of noise heard by the patients and evaluating the difference of noise by sound insulation material. A sound meter was placed in a water phantom made outside the magnetic field of the MRI to measure the noise using four sequences (EPI, T1, T2, GRE) and compared it to the sound felt by the patient.

Findings: As a result, the average noise felt by the patient was measured to be 92.5 dB at EPI, 73.1 dB at T1, 87.4 dB at T2, and finally 74.4 dB at GRE. The average noise when the earplug was worn was measured to be 84.4 dB at EPI, 66.3 dB at T1, 79.4 dB at T2, and 67.7 dB at GRE. The average noise value when the headset was worn was measured to be 78.2 dB at EPI, 61.3 dB at T1, 74.4 dB at T2, and 65.3 dB at GRE. Finally, the average noise when both earplug and headset were simultaneously worn was measured to be 77.4 dB at EPI, 60.5 dB at T1, 73.3 dB at T2, and 63.4 dB at GRE respectively. Based on the above result, the most effective sound insulation was made when both earplug and headset were worn at the same time, the next effective sound insulation method was headset wearing, and the least sound insulation method was earplug wearing.

Improvements/Applications: If it is not possible to apply a fundamental management method to eliminate the causes of noise, which is difficult to practice in actual clinical practice, it is suggested that hearing protection gear should be actively used to reduce the degree of noise-exposed to patients.