1. Institute of Medical Sciences, Foresterhill, University of Aberdeen, AB252ZD Aberdeen, United Kingdom
2. Centre for Sensing and Imaging Science, School of Science, Loughborough University, LB11 3TU Loughborough, United Kingdom
3. Amsterdam UMC, Vrije Universiteit, dept. Radiology and Nuclear Medicine, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
4. CNR-SCITEC, via Mancinelli 7, 20131 Milan, Italy