A Total Variation Spatial Prior for the Estimation of Perfusion & Transit Time Maps in PASL-MRI

Blood-tissue exchange is a fundamental physiologic process that can be quantified by ASL methods. Commonly-used kinetic models for characterising blood-tissue magnetisation exchange assume fast mixing in the tissue; this assumption may result in large systematic errors in, e.g., tissue blood flow estimates. We develop a model of IV-EV exchange that accounts for diffusion within the tissue compartment; the extravascular magnetisation and the total magnetic moment are obtained and a criterion for the validity of the kinetic modelling approach is given. The model is applied to ASL of brain and myocardium.