1. Institute of Information Science and Technologies of the National Research Council of Italy,56124 Pisa,Italy
2. Foundation for Research and Technology Hellas,Ioannina,Greece
3. Institute of Computer Science,Foundation for Research and Technology Hellas,Heraklion,Greece
4. University of Turin,Department of Surgical Sciences,10126 Turin,Italy
5. Computational Clinical Imaging Group,Champalimaud Foundation,Lisboa,Portugal