1. Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Science Center, 600 Highland Ave, Madison, WI 53792-3252.
2. im3D Medical Imaging Laboratory, Turin, Italy.
3. Imaging Unit, Candiolo Cancer Institute FPO-IRCCS, Turin, Italy.
4. Digestive Endoscopy Unit, Nuovo Regina Margherita Hospital, Rome, Italy.