Velocity Selective Arterial Spin Labeling at 7T

Motivation: Velocity selective (VS)-ASL can be of great added benefit for fMRI at ultra-high field because of its specificity and ATT-insensitivity. Goal(s): Our goal was to show the feasibility of VS-ASL at 7T with minimal TR, which involves minimizing SAR and timing parameters within the sequence. Approach: VS-ASL was implemented using BIR4 labeling module and compared to the robust FAIR ASL. Image quality was measured based on quantified ASL-signal and tSNR-efficiency. Results: Good agreement between FAIR and VSSinv-ASL was found. VSSinv-ASL was used to create intrinsic BGS without additional SAR. A shortest TR of 4500ms was achieved which could potentially be shorted with pTx. Impact: We showed the feasibility of Velocity Selective (VS)-ASL at UHF and the application in fMRI. VS-ASL showed comparable but less homogeneous tSNR as FAIR. VS-ASL is of added benefit for fMRI at ultra-high field because of its specificity and ATT-insensitivity.