Active noise control of simulated magnetic resonance imaging response

Magnetic resonance imaging (MRI) is a powerful medical diagnostic tool that is capable of producing high quality images that other technologies have not been able to achieve. Unfortunately, the imaging process results in acoustic emissions great enough to be annoying and potentially hazardous to the patient and any healthcare provider in the vicinity of the scanner. In this study, an active noise control scheme is proposed and modeled for pre-recorded sound and gradient signals from a 4-Tesla MRI scanner. The recorded MRI response is played back through a high fidelity stereo system in a sound quality studio while the gradient signals are input to an active controller which generates a cancellation signal that is played through a set of headphones. Numerous controller parameters are tested and tuned to optimize performance. The results show a substantial reduction at the principal harmonic, and a reduction of up to 12 dB for the entire sound spectrum is achieved.