Acoustic Noise Levels in High‐field Magnetic Resonance Imaging Scanners

Abstract

Abstract7‐Tesla (T) magnetic resonance imaging may allow for higher resolution images but may produce greater acoustic noise than 1.5‐ and 3‐T scanners. We sought to characterize the intensity of acoustic noise from 7‐ versus 3‐T scanners. A‐weighted sound pressure levels from 5 types of pulse sequences used for brain and inner ear imaging in 3‐ and 7‐T scanners were measured. Time‐averaged sound level and maximum sound levels generated for each sequence were compared. Time‐averaged sound levels exceeded 95 dB and reached maximums above 105 dB on the majority of 3‐ and 7‐T scans. The mean time‐averaged sound level and maximum sound level across pulse sequences were greater in 7‐ than 3‐T (105.6 vs 91.4, P = .01; 114.0 vs. 96.5 dB, P < .01). 7‐ and 3‐T magnetic resonance imaging scanners produce high levels of acoustic noise that exceed acceptable safety limits, emphasizing the need for active and passive noise protection.