1. Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
2. Department of Neurology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
3. Department of Neuroradiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
4. Department of Diagnostic and Interventional Radiology, Eberhard Karls University, Tuebingen, Germany