Sequence noise and vibration optimization based on frequency response function

Motivation: Sequence noise and vibration can cause discomfort for the subjects, and may also affect image quality. Goal(s): To reduce the sequence noise and vibration by optimizing gradient parameters. Approach: Gradient parameters were iteratively optimized with the frequency response function. The sequence can be divided into three parts according to their contribution to noise and vibration, and can be optimized respectively. Results: For EPI-DWI (diffusion weighted echo planar imaging), with the same b-value, reducing the bandwidth by 25Hz, and increasing the TE by 4.5ms, the noise can be reduced by 8.2 dB(A), and the vibration can be reduced by up to 4 dB. Impact: This method has potential to minimize the gradient induced noise and vibration within the allowable adjustment range of parameters. Together with the hardware optimization in the main frequency band of the sequence vibration, it can potentially improve subject comfort significantly.