Spatial dependency and the role of local susceptibility for velocity selective arterial spin labeling (VS-ASL) relative tagging efficiency using accelerated 3D radial sampling with a BIR-8 preparation.

We demonstrate an approach to map the relative tagging efficiency and show application of this methodology to a novel BIR-8 preparation recently proposed in the literature. We present results showing rapid flow in the presence of local susceptibility gradients can lead to complicated signal modulations in both tag and control images and reduced tagging efficiency.