1Centre for Imaging Sciences, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, United Kingdom, 2School of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom, 3CRUK & EPSRC Cancer Imaging Centre in Cambridge & Manchester, Manchester, United Kingdom, 4Melbourne Brain Centre, The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 5Bioxydyn Limited, Manchester, United Kingdom