Premium
Sound‐Level Measurements and Calculations of Safe Noise Dosage During EPI at 3 T
Author(s) -
Foster John R.,
Hall Deborah A.,
Summerfield A. Quentin,
Palmer Alan R.,
Bowtell Richard W.
Publication year - 2000
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/1522-2586(200007)12:1<157::aid-jmri17>3.0.co;2-m
Subject(s) - noise (video) , scanner , sound pressure , acoustics , noise exposure , sound level meter , noise reduction , noise level , physics , hearing loss , medicine , audiology , computer science , optics , artificial intelligence , image (mathematics)
This paper describes systematic methods for measuring and controlling sound levels within a magnetic resonance scanner. The methods are illustrated by application to the acoustic noise generated by a 3 T scanner during echoplanar imaging (EPI). Across five measurement sessions, sound pressure levels at the center of the head gradient coil ranged from 122 to 131 dB SPL [123 to 132 dB(A)]. For protection against damaging noise exposure, UK and US industrial guidelines stipulate that the maximum permitted daily noise dosage is equivalent to 90 dB(A) for 8 hours, where noise dosage is a function of the level of an acoustic signal and the length of exposure to it. Without hearing protection, this equivalent level would be exceeded by less than 5 seconds of exposure to the measured levels of scanner acoustic noise. These findings highlight the importance of noise reduction and hearing protection for those exposed to the acoustic noise generated during EPI. J. Magn. Reson. Imaging 2000;12:157–163. © 2000 Wiley‐Liss, Inc.