A VERSE algorithm with additional acoustic noise constraints

Introduction At higher static field strengths of 7T and above specific absorption rate (SAR) and acoustic sound pressure level (SPL) pose limitations on the pulse sequence design. To overcome SAR limitations, the VERSE principle can be used [1]. Here, the envelope of existing rf pulses are modified together with the shape of the slice-selection gradient to selectively reduce high B1 amplitudes during the (often central) portions of the rf pulse. With VERSE, a gradient amplitude modulation is introduced, that can cause additional noise in the pulse sequence. In this work a general VERSE algorithm is presented, that reduces both the B1 amplitude (and thus SAR) and the acoustic noise of the gradient for arbitrary RF pulses. The method is demonstrated for SINC rf pulses.