1. Department of Internal Medicine, Division of Angiology, Medical University of Graz, Graz, Austria
2. Department of Neurology, Division of General Neurology, Medical University of Graz, Graz, Austria
3. Department of Radiology, Division of Neuroradiology, Vascular and Interventional Radiology, Medical University of Graz, Graz, Austria
4. Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria