[1] Chelsea & Westminster Hosp NHS Fdn Trust, Dept Radiol, London, England
[2] Chelsea & Westminster Hosp NHS Fdn Trust, Dept Colorectal Surg, London, England
[3] Univ Autonoma Barcelona UAB, Vall dHebron Univ Hosp, Colorectal Surg, Barcelona, Spain
[4] Univ Campania Luigi Vanvitelli, Dept Adv Med & Surg Sci, Naples, Italy