1. Department of Radiology, University Hospital Muenser, Westfalian Wilhelms-University Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany
2. Department of Interventional Neuroradiology, Westfalian Wilhelms-University Muenster and University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany
3. Department of Neurology, Westfalian Wilhelms-University Muenster and University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany
4. Clinic and Policlinic for Diagnostic and Interventional Neuroradiology, University Hospital Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany