1. University Medical Center Utrecht, Image Sciences Institute, Q.02.4.45, P.O. Box 85500, Heidelberglaan 100, Utrecht 3508 GA, The Netherlands
2. Erasmus Medical Center, Thoraxcenter, Department of Cardiology, ‘s-Gravendijkwal 230, Rotterdam 3015 CE, The Netherlands
3. Erasmus Medical Center, Thoraxcenter, Department of Biomedical Engineering, ‘s-Gravendijkwal 230, Rotterdam 3015 CE, The Netherlands