[1] Univ Palermo, Sect Radiol, Palermo, Italy
[2] Univ Palermo, Gastroenterol DiBiMiS, Palermo, Italy
[3] Duke Univ, Med Ctr, Dept Radiol, Durham, NC 27710 USA
[4] Univ Pittsburgh, Dept Radiol, Med Ctr, Pittsburgh, PA 15260 USA
[5] Univ Paris Diderot, Beaujon Univ Hosp Paris, Sorbonne Paris Cite, Dept Radiol,IPMA Lab,INSERM U773, Clichy, France