1Oxford Centre for Functional MRI of the Brain (FMRIB), University of Oxford, Oxford, United Kingdom, 2Section for Biomedical Image Analysis (SBIA), University of Pennsylvania, Philadelphia, PA, United States, 3Oxford e-Research Centre, University of Oxford, Oxford, United Kingdom, 4Faculty of Information Technology and Bionics, Pazmany Peter Catholic University, Budapest, Hungary, 5Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom