Quiet ASL with Non-rephasing Labeling Gradients and Silent Readout

Motivation: ASL has been used in pediatric perfusion imaging and resting-state fMRI studies. However, the recommended pCASL sequences generate acoustic noise because of the maximum slew rate employed in the labeling and acquisition parts. Goal(s): To develop a pCASL sequence with reduced acoustic noise. Approach: Paired triangle-shape gradients without rephasing gradients was proposed to provide pseudo continuous arterial labeling and the WASPI readout, instead of GRASE, was optimized for ASL acquisition. Results: The proposed quiet pCASL sequence reduced acoustic noise by 47% in the labeling part and 96% in the acquisition part while maintaining competitive image quality compared to conventional pCASL. Impact: The proposed quiet ASL provided a novel approach to label blood. It may improve patients experience and have a great potential in resting state fMRI studies.