[1] Univ Vienna, Sch Med, Dept Gastroenterol & Hepatol, A-1090 Vienna, Austria
[2] Univ Vienna, Sch Med, Dept Intervent Radiol, A-1090 Vienna, Austria
[3] Univ Vienna, Sch Med, Dept Med Stat, A-1090 Vienna, Austria
[4] Kaiser Franz Josef Spital, Dept Radiol, Vienna, Austria
[5] Krankenhaus Elisabethinen, Dept Gastroenterol & Hepatol, Linz, Austria