Repeatability of Blood-Brain Barrier Diffusion Weighted Arterial Spin Labeling MRI at Different Post-Label Delays

Motivation: Anomalous blood-brain barrier (BBB) water transfer rate (Kw) has the potential to be a novel biomarker for neurological disorders. Goal(s): However, additional studies are needed to affirm the reliability of MRI sequences that assess Kw. Approach: This in vivo study sought to determine the intrasession repeatability of the single-delay diffusion-weighted (DW) arterial spin labeling (ASL) MRI sequence at different DW post-label delays (PLDs). [1]Results: Our findings confirmed that cerebral blood flow (CBF) and Kw were most stable at a DW PLD of 1800ms and that there exists a significant linear correlation between arterial transit time (ATT) and Kw. Impact: Our findings show that for single-delay diffusion weighted (DW) ASL MRI, properly selecting the DW PLD and consideration of ATT are crucial for robust BBB water permeability measurements. Studies like ours are necessary before Kw imaging in different disease states.