1 Department of Radiology and Nuclear Medicine, Radboud University Nijmegen Medical Center, Geert Grooteplein 10, Postbus 9101, 6500 HB, Nijmegen, the Netherlands. Anton.Meijer@radboudumc.nl.
2 Department of Radiology and Nuclear Medicine, Radboud University Nijmegen Medical Center, Geert Grooteplein 10, Postbus 9101, 6500 HB, Nijmegen, the Netherlands.
3 Department of Neurosurgery, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands.