Michael A. Chappell1,2, Esben T. Petersen3, Mark W. Woolrich2, Xavier Golay4, Stephen J. Payne1
1Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom; 2FMRIB Centre, University of Oxford, Oxford, United Kingdom; 3Clinical Imaging Research Center, NUS-A*STAR, Singapore; 4Institute of Neurology, University College, London, United Kingdom
The QUASAR Arterial Spin Labelling (ASL) approach is unique in making use of a variety of flow suppressed and non-suppressed data. This makes model-free analysis feasible, it also is advantageous for model-based strategies, since the different regimes can be used to model more accurately the arterial and tissue signals. Here a novel model-based strategy is proposed that models the contribution of label in the arteries as magnitude and dominant direction of arterial blood flow. This provides a more appropriate comparison to model-free approaches and also permits different models of label dispersion to be more rigorously tested.