Temporary Hearing Threshold Shift in Healthy Volunteers with Hearing Protection Caused by Acoustic Noise Exposure during 3-T Multisequence MR Neuroimaging

Purpose: To determine whether a single 51-minute exposure to acoustic noise during 3-T multisequence magnetic resonance (MR) neuroimaging could affect the hearing threshold of healthy adults with earplugs and sponge mats as hearing protection. Materials and Methods: With earplugs and motion-refraining sponge mats as hearing protection, 26 healthy young adults underwent 3-T MR neuroimaging imaging that included T1-weighted three-dimensional gradient-echo sequence, T2-weighted fast spin-echo sequence, diffusion-tensor imaging, diffusion-kurtosis imaging, T2*-weighted three-dimensional multiecho gradient-echo sequence, and blood oxygen level-dependent imaging. Automated auditory brainstem response (ABR) was used to measure the hearing thresholds within 24 hours before, within 20 minutes after, and 25 days after the MR examination. One-way repeated-measure analysis of variance with Bonferroni adjustment was used to compare automated ABR results among the three tests and partial eta(2) (eta(2)(p)) was reported as a measure of effect size. Results: Automated ABR results showed significantly increased mean threshold shift of 5.0 dB +/- 8.1 (standard deviation) (left ear: 4.8 dB +/- 9.2 [95% confidence interval: 1.09, 8.53], eta(2)(p) = 0.221, P=.013; right ear: 5.2 dB +/- 6.9 [95% confidence interval: 2.36, 8.02], eta(2)(p) = 0.364, P=.001) immediately after the MR examination compared with the baseline study. This shift is below the temporary threshold shift of 40-50 dB that is associated with cochlea nerve changes. Automated ABR obtained at day 25 after MR imaging showed no significant differences from baseline (left ear: 22.3 dB +/- 8.6 [95% confidence interval: 25.79, 1.78], eta(2)(p) = 0.069, P=.185; right ear: 0.4 dB +/- 7.3 [95% confidence interval: 23.35, 2.58], eta(2)(p) = 0.003, P=.791). Conclusion: A 3-T MR neuroimaging examination with the acoustic noise at equivalent sound pressure level of 103.5-111.3 dBA lasting 51 minutes can cause temporary hearing threshold shift in healthy volunteers with hearing protection.