Program Information
Inter-Vendor Acoustic Noise Comparison On Wide-Bore 3T MRI Scanners
A Panda*, J Hanson , Y Zhou , J James , Mayo Clinic, Arizona, Scottsdale, AZ
Presentations
SU-K-708-9 (Sunday, July 30, 2017) 4:00 PM - 6:00 PM Room: 708
Purpose: MRI acoustic noise represents hazard to patients undergoing MRI and to staff present in the scanner room. The FDA considers A-weighted root-mean-square sound pressure level greater than 99 dBA in MRI to be of significant risk needing hearing protection. The goal of this study was to perform inter-vendor acoustic noise comparison on identical field strengths and bore sizes to evaluate appropriate baseline hearing protection requirements.
Methods: Acoustic noise measurements were performed on Siemens Skyra and GE 750w, both 3.0T wide-bore MRI scanners using an acoustic meter (3M Sound Examiner, Model SE-402). The measurements were made at three locations: 1) center of the scanner bore, 2) entrance of the bore and 3) at 200 G line (~ 1 meter from the bore entrance). Per IEC-601-2-33 recommendations, the sequences were run for at least 1 min and A-weighted sound pressure levels were measured to obtain dBA readings.
Results: At the center of the bore, EPI and HASTE sequences recorded the highest noise values for Siemens Skyra, reaching 108.2 dBA and 107.2 dBA peak, respectively, and AX T2 FRFSE and CUBE T1 FSE sequences were the loudest for GE 750w, both reaching 145 dBA peak. All sequences measured between 100 – 110 dbA peak at the entrance of the bore and at 200 Gauss line on both the GE and Siemens scanner.
Conclusion: MRI scanners produce noise levels that can exceed FDA significant risk threshold for both patients and staff. Sequences requiring high gradient performance and fast switching, e.g. EPI or TSE, produce the loudest noise levels. Acoustic noise peak for GE 750w was significantly higher (~30 dBA) at the center of the bore than Siemens. It is recommended that a facility with multiple vendor MRI scanners to measure acoustic noise levels on all vendors to determine adequate baseline hearing protection.
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