1. From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland (B.B., M.M., S.O., H.A., R.M.); Department of Radiology, University Hospital of Cologne, Cologne, Germany (B.B., D.M.); Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland (S.O., R.M.); and Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland (R.M.).