Synopsis

ASL is a non-invasive MRI method for quantitative mapping of cerebral blood flow (CBF). In this talk, I describe the two main categories of ASL – pseudocontinuous (pCASL) and pulsed (PASL) – and explain how the images acquired using these different acquisition schemes can be converted into CBF maps, using a general tracer kinetic model. I describe how ASL data can be acquired with either single or multiple inflow delay times, and the pros/cons of these two approaches. Lastly, I discuss some practical considerations (imaging method, background suppression) which also affect the quality and accuracy of ASL CBF maps.