1. Visualization, Virtual Reality and Graphics Interaction Research Group, UPC-BarcelonaTech, 08034 Barcelona, Spain
2. Digestive Department, University Hospital General de Catalunya, 08190 Barcelona, Spain
3. Digestive System Research Unit, University Hospital Vall d’Hebron, 08035 Barcelona, Spain
4. Departament de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
5. Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Ciberehd, 28029 Madrid, Spain