[1] Univ Florence, Dept Clin Physiopathol, Radiodiagnost Sect, I-50139 Florence, Italy
[2] Canc Res & Prevent Inst ISPO, I-50139 Florence, Italy
[3] Inst Canc Res & Treatment, Radiol Unit, I-10060 Turin, Italy
[4] Univ Florence, Dept Clin Physiopathol, Gastroenterol Sect, I-50139 Florence, Italy