Pulse sequence generation systems and methods of reducing acoustic noise in magnetic resonance systems

A pulse sequence generation computing device for a magnetic resonance imaging (MRI) system, the pulse sequence generation computing device comprising at least one processor in communication with at least one memory device, and the at least one processor programmed to:

• receive a pulse sequence including a plurality of gradient pulses;
• provide a pulse sequence threshold function that corresponds to an acoustic noise reduction level of acoustic noise produced by switching gradients in the MRI system, the pulse sequence threshold function indicating a plurality of threshold amplitudes of the gradient pulses and a plurality of threshold slew rates of the gradient pulses each associated with one of the plurality of threshold amplitudes;
• for each gradient pulse in the pulse sequence,
• determine an amplitude of the gradient pulse and a slew rate of the gradient pulse;
• determine a threshold amplitude corresponding to the determined slew rate and a threshold slew rate corresponding to the determined amplitude;
• compare the determined amplitude to the threshold amplitude and the determined slew rate to the threshold slew rate;
• and
• if the determined amplitude exceeds the amplitude threshold or the determined slew rate exceeds the slew rate threshold, the at least one processor configured to modify the gradient pulse by adjusting at least one of the amplitude and the slew rate of the gradient pulse to an amplitude and a slew rate as defined by the pulse sequence threshold function.

A computer implemented method of generating a pulse sequence in a magnetic resonance imaging (MRI) system, comprising:

• receiving a pulse sequence including a plurality of gradient pulses;
• providing a pulse sequence threshold function that corresponds to an acoustic noise reduction level of acoustic noise produced by switching gradients in the MRI system, the pulse sequence threshold function indicating a plurality of threshold amplitudes of the gradient pulses and a plurality of threshold slew rates of the gradient pulses each associated with one of the plurality of threshold amplitudes;
• for each gradient pulse in the pulse sequence,
• determining an amplitude of the gradient pulse and a slew rate of the gradient pulse;
• determining a threshold amplitude corresponding to the determined slew rate and a threshold slew rate corresponding to the determined amplitude;
• comparing the determined amplitude to the threshold amplitude and the determined slew rate to the threshold slew rate;
• and
• modifying, if the determined amplitude exceeds the amplitude threshold or the determined slew rate exceeds the slew rate threshold, the gradient pulse by adjusting at least one of the amplitude and the slew rate of the gradient pulse to an amplitude and a slew rate as defined by the pulse sequence threshold function;
• and
• causing the modified pulse sequence to be generated by the MRI system.