Whole-brain Perfusion Mapping at 7T by SAR-efficient Non-segmented 3D EPI-pCASL

Abstract

Due to high specific absorption rate (SAR), it has not been easy to apply pseudo-continuous arterial spin labeling (pCASL) at 7T human MRI, especially with 3D readouts. In this study, non-segmented 3D-EPI-pCASL is proposed for whole-brain perfusion mapping. SAR was reduced by multiple low-flip-angle water-excitation rectangular RF pulses for 3D EPI. The proposed 3D-EPI-pCASL produced consistent perfusion maps at both 3T and 7T compared to 2D-EPI-pCASL which was available only at 3T because of SAR. The high temporal resolution of the proposed non-segmented 3D-EPI-pCASL enabled us to get a whole-brain 3D pCASL fMRI map at 7T for the first time.