Modal analysis and acoustic noise characterization of a 4T MRI gradient coil insert

Abstract

AbstractHigh magnetic field strength and high‐speed gradient coil current switching are combining to yield high acoustic sound pressure levels (SPL) in and around magnetic resonance imaging (MRI) scanners. Studies have already been conducted that partially characterize this sound field, and various methods have been investigated in an attempt to attenuate the noise generated. To more fully characterize and predict the vibration and acoustic response of a gradient coil inside a scanner, a series of finite element analysis (FEA), vibro‐acoustic analysis, and experimental measurements were carried out. The FEA and vibro‐acoustic model used was based on specific internal and external structural dimensions and the material physical properties of a gradient coil insert. The model‐based results were verified through experimental vibration and acoustic testing of the same gradient coil. It was found that the experimental analysis results were in good agreement with the model‐based results in all cases. The numerical methods developed in this study could provide a basis for the virtual testing of gradient coil designs that will allow the prediction of vibration and acoustic behavior. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 22B: 37–49, 2004