1. Department of Biomechanical Engineering; University of Twente; P. O. Box 217 7500 AE Enschede Overijsel Netherlands
2. Faculty of Engineering of University of Porto; Rua Dr. Roberto Frias 4200-465 Porto Portugal
3. Department of Radiology; Brigham and Women's Hospital and Harvard Medical School; 75 Francis Street Boston MA 02119 USA
4. Department of Radiology; Jeroen Bosch Hospital; Nieuwstraat 34 5211 NL's-Hertogenbosch The Netherlands
5. Department of Biomedical Engineering; University of Groningen and University Medical Centre Groningen; Antonius Deusinglaan 1 9713 AV Groningen The Netherlands