1. University of Freiburg; Department of Cardiology and Angiology I, Heart Center; Freiburg Germany
2. University of Sheffield; Academic Unit of Radiology; Sheffield UK
3. Faculty of Medicine and Medical Center, University of Freiburg; Institute for Medical Biometry and Statistics; Freiburg Germany
4. Medical Center - University of Freiburg; Institute for Evidence in Medicine (for Cochrane Germany Foundation); Breisacher Straße 153 Freiburg Germany 79110