1. Department of Neuroradiology, University Medical Center Hamburg Eppendorf, Germany
2. Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg Eppendorf, Germany
3. Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg Eppendorf, Germany
4. Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg
5. Dr. HD Nagel, Science & Technology for Radiology, Buchholz, Germany