Achieving Robust Labeling Above the Circle of Willis with Vessel-Encoded Arterial Spin Labeling

Motivation: The ability to distinguish arterial blood supply above CoW is crucial in the study of collateral circulation, but it is challenging due to the complex positioning of arteries around the CoW. Goal(s): To achieve a robust vascular territories separation above CoW. Approach: We propose improvements to the original OES method, optimizing its SNR efficiency while minimizing high spatial frequencies to avoid mislabeling. We have also selected a set of PCASL parameters that facilitate thin-slice labeling and ensure high labeling efficiency to overcome issues related to vascular tortuosity. Results: Combining optimized parameters and improved OES, the vascular territories separation has significantly improved. Impact: Our study optimized the fully automatic encoding pattern design above the circle of Willis, and achieved a robust vascular territories separation, combining with optimized PCASL parameters.