Arterial Transit Time and Cerebral Blood Flow Estimation in Multi-delay Pseudo-continuous Arterial Spin Labeling

Motivation: The inherent low SNR of ASL limits the accuracy of cerebral blood flow (CBF) and arterial transit time (ATT) quantification. Although a postlabeling delay weighted delay method has been proposed, its benefits are not clear and cannot be used in general delay protocols. Goal(s): To compare multi-delay protocols and estimators. Approach: A general weighted delay estimator was proposed. Its performance was evaluated using Monte Carlo simulations and in-vivo experiments, compared to the direct model fitting. Results: The multi-PLD/LD protocols provided a superior estimation compared to the other protocols. The L2-norm fitting and the GWD estimator may provide improved CBF and ATT estimation, respectively. Impact: The multi-PLD/LD protocols provided superior accuracy and precision which may provide a feasible option for quantifying the dynamic characteristics of perfusion. The L2-norm fitting and the general weighted delay method may provide improved CBF and ATT estimation, respectively.