[1] Univ Milan, L Sacco Hosp, Dept Biomed & Clin Sci, Gastroenterol Unit, Milan, Italy
[2] Fatebenefratelli L Sacco Univ Hosp, Radiol Unit, Milan, Italy
[3] Fdn IRCCS Policlin San Matteo, Clin Epidemiol & Biometer Unit, Pavia, Italy
[4] Univ Perugia, Dept Med & Surg, Gastroenterol Hepatol & Digest Endoscopy Sect, Perugia, Italy
[5] Santa Maria Misericordia Hosp, Gastroenterol Unit, Perugia, Italy