1. Medical student, University of Liège, Liège, Belgium;
2. Dept. of cardiovascular and thoracic surgery, University of Liège, CHU Sart-Tilman, Liège, Belgium (Prof. R Limet);
3. Dept. of Radiology, Clinique Notre Dame, Hermalle-sous-Argenteau, Belgium;
4. Dept. of Anesthesiology, Clinique Notre Dame, Hermalle-sous-Argenteau, Belgium.