MRI Scanner Vibration and Acoustic Noise

Abstract

To characterize the vibration properties as well as the acoustic noise properties of the gradient coil, a finite element (FE) model was developed using the dimensional design specifications of an available gradient coil insert and the concentration of the copper windings in the coil. This FE model was then validated using experimentally collected vibration data (experimental modal testing of the gradient coil in a free-free state (no boundary constraints)). Based on the validated FE model, boundary conditions (supports) were added to the model to simulate the operating condition when the gradient coil insert is in place in an MRI machine. Vibration analysis results from the FE model were again validated through experimental vibration testing, this time with the gradient coil insert installed in the MRI scanner and excited using swept sinusoidal time waveforms. The simulation results from the computational acoustic noise model were also validated through experimental noise measurement from the gradient coil insert in the MRI scanner using swept sinusoidal time waveform inputs. Comparisons show that the FE model predicts the vibration properties and the computational acoustic noise model predicts the noise characteristic properties extremely accurately.