[1] Dudley Grp Hosp NHS Trust, Dept Gastroenterol, Dudley, England
[2] Univ Hosp Birmingham NHS Fdn Trust, Dept Hlth Informat, Birmingham, W Midlands, England
[3] Natl Univ Singapore Hosp, Dept Diagnost Imaging, Singapore, Singapore
[4] Univ Hosp Birmingham NHS Fdn Trust, Dept Radiol, Birmingham, W Midlands, England
[5] Univ Birmingham, Inst Canc & Genom Sci, Birmingham, W Midlands, England
[6] Sandwell & West Birmingham Hosp NHS Trust, Dept Gastroenterol, West Bromwich, England