1. Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
2. Department of Radiology and Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
3. Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
4. Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany