A Versatile Setup for Measuring Complex Gradient-to-Acoustic-Noise or Gradient-to-Vibration Transfer Functions via the Scanner’s ADC

Abstract

Motivation: Knowledge of gradient transfer functions in situ would allow predictions about the auditory spectrum of arbitrary MRI sequences during execution, to achieve individualized assessments of potentially harmful sound levels or damaging vibrations of the gradient coil. Goal(s): Our goal was to enable the integration of appropriate sound or vibration measurements into the routine operation of a scanner. Approach: A modulator box was developed that emulates a receiver coil and permits the simultaneous digitization of variable sensor signals (e.g., microphones and accelerometers) by the scanner's ADC. Results: Realistic gradient-to-acoustic-noise and gradient-to-vibration transfer functions were determined without the need of synchronizing external devices. Impact: A versatile hardware concept has been developed that allows integration into a clinical scanner and prediction of the sound level inside the bore from the frequency spectrum of the input signal defined by the pulse sequence during scanning.