1. Department of Neurosurgery, Justus-Liebig-University Gießen, Gießen, Germany
2. Department of Neurosurgery, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
3. Institute of Neuroradiology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
4. Institute of Neuroradiology, Ingolstadt Hospital, Ingolstadt, Germany