Acoustic noise analysis and prediction in a 4‐T MRI scanner

Abstract

AbstractGradient coil induced acoustic noise was measured in a 4 Tesla MRI scanner. To characterize the sound distribution, a series of measurements were taken along the centreline of the gradient coil using echo planar imaging (EPI) sequences as inputs. The acoustic noise frequency spectra were calculated and used to compare the acoustic response relative to the spatial distribution along the centreline. Using the standard approach of frequency response function (FRF) measurement with sinusoidal sweep inputs, the sound pressure levels (SPLs) due to EPI input sequences were predicted. The results showed that the predictions using the FRF were very close to the measured SPLs. Although previously known as an accurate acoustic noise characterization tool, frequency response functions have been shown here to be a useful method for predicting acoustic noise levels due to other scanning sequences. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 21B: 19–25, 2004.