Active control of magnetic resonance imaging response using inverse modeling

Magnetic resonance imaging (MRI), a procedure for medical diagnosis and biomedical research, generates significant levels of acoustic emissions during operation.The noise is normally dominated by clusters of harmonics throughout the audio spectrum. In this paper, an active noise control scheme using the inverse modeling technique is proposed and studied for pre-recorded MRI response obtained during the operation of a 4 T whole-body MRI scanner. The recorded MRI acoustic noise is played back through a high fidelity stereo system in a sound quality room and controlled using a headset equipped with the proposed active controller. The results demonstrate that noise reduction of over 20 dB is measured during the initial baseline test. Additional reduction is achieved by modifying the response of the secondary path, which extends the effective frequency range to 5 kHz. Results comparing convergence rates are also discussed.