Introduction

Abstract

As defined in the European Crohn’s and Colitis Organization (ECCO) guidelines, Ulcerative Colitis (UC) is a chronic inflammatory condition involving a non-granulomatous mucosal inflammation that probably arises from an interaction between genetic and environmental factors. UC commences in the rectum and extends proximally in a confluent manner to affect a variable extent of the large bowel. Traditionally, diagnostic imaging of UC relied on double-contrast barium enema, which in experienced hands could provide useful information concerning the extent of colonic disease, although limited to the mucosal surface. Currently, thanks to dramatic technical improvements, imaging modalities such as multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and ultrasound are increasingly employed at referral Centres to investigate UC patients in both urgent and elective settings. Complementary to endoscopy, cross-sectional imaging comprehensively investigates the intestinal disease, associated perivisceral changes and extraintestinal manifestations. Furthermore, diagnostic imaging is needed to stage neoplasms and perianal inflammatory diseases in UC patients. Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is currently the gold standard procedure for surgical treatment of UC. Knowledge of the surgical technique and of normal imaging appearances of the “pouch” reservoir are needed to interpret early postoperative studies and to assess chronic pouch-related disorders.