Hybrid phase-sensitive 4D MRA and perfusion imaging using dynamic arterial spin labeling with stack-of-stars golden-angle radial acquisition

Motivation: Comprehensively characterizing cerebrovascular events including dynamic blood flow patterns and downstream perfusion is important in clinical diagnosis of cerebrovascular disorders. Goal(s): To develop a time-efficient phase-sensitive ASL technique (PS-ASL) that provides high-quality time-resolved 4D-MRA and perfusion imaging within single scan. Approach: PS-ASL sequence was designed by combining pCASL and PASL preparations with stack-of-stars golden-angle radial acquisition and a self-constraint low-rank subspace reconstruction. The label and control pulse modules alternated between pCASL and PASL preparations in each TR. Phase-sensitive subtraction between control and label yields 4D-MRA from PASL and perfusion from pCASL. Results: Both dynamic 4D-MRA and perfusion maps were successfully obtained by PS-ASL. Impact: The developed PS-ASL technique could be a potential powerful imaging tool in clinical applications, which provides detailed characterization of blood flow from both arterial and capillary beds in a single sequence.