Arterial Transit Time Effects in Pulsed Arterial Spin Labeling CBF Mapping: Insight from a PET and MR Study of Normal Human Subjects

Maolin Qiu¹, Jinghua Wang¹, Jagriti Arora¹, Yuenan Wang¹, Heyonjin Kim¹, Nallakkandi Rajeevan¹, Beata Planeta-Wilson¹, David Weinzimmer¹, Richard E. Carson^1,2, Robert Todd Constable^1,2

Arterial transit times (ATT) were estimated using both the perfusion-induced changes in image intensity measured by pulse arterial spin labeling (ASL) and the absolute cerebral blood flow (CBF) quantified by positron emission tomography (PET) on the same group of normal healthy subjects. This work demonstrates the marked dependence of arterial transit times upon the location of the imaging and labeling slabs and quantifies the effect of ATT on measurement of CBF. The results of this study should aid in the interpretation of ASL-based CBF studies, while also providing spatially specific data on ATT values that may aid in optimizing the imaging parameters in ASL acquisitions.