1. Department of Radiology, Diagnostic and Interventional Radiology, University Hospital Tuebingen, Tuebingen, Germany
2. Medical Clinic B, Cardiovascular Research Lab, Medical Faculty, Department of Cardiology, Pneumology and Vascular Diseases, University Hospital Duesseldorf, Duesseldorf, Germany
3. Clinic of Cardiology, West German Heart and Vascular Centre Essen, Medical School, University of Essen, Essen, Germany
4. Institute of Pathophysiology, West German Heart and Vascular Centre Essen, University of Essen Medical School, Germany