Comparison of Arterial Transit Times Estimated Using FEAST and LL-FAIR

Yufen Chen¹, jiongjiong Wang¹, Marc Korczykowski¹, John A. Detre¹

Arterial transit time is a physiological parameter measured by arterial spin labeling. Look-locker (LL-FAIR) and Flow Encoded Arterial Spin Tagging (FEAST) are two ASL variants that can quantify arterial transit time. Comparison of the estimated arterial transit times show good correlation between the two methods in gray matter of major vascular regions (r=0.46, p=0.02), despite a difference of ~1s. This is because FEAST is sensitive to arterial transit time to tissue, while LL-FAIR measures the arrival of labeled blood in the imaging slice. Combination of the two can improve understanding of pathology of cerebrovascular diseases.