1 BioFlow Chimère Laboratory, Department of Medical Image Processing, CHU Amiens, University of Picardy Jules Verne, Amiens, France.
2 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Box 167, Addenbrookes Hospital, Cambridge, Cb20QQ, UK. mc141@medschl.cam.ac.uk.
3 Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Box 167, Addenbrookes Hospital, Cambridge, Cb20QQ, UK.