Helical CT diagnosis of small bowel obstruction in the acute clinical setting.

Definite confirmation or exclusion closed loop obstruction (CLO) is one of the most difficult tasks the radiologist has to face in the clinical practice. Aim of this retrospective work was to study the value of spiral computed tomography (CT) in the diagnosis of closed loop obstruction complicated by intestinal ischemia. The state of the art CT signs of closed loop obstruction were taken into consideration. Serrated beaks with poor or no contrast enhancement of the bowel walls, ascites or engorgement of the mesenteric vasculature allowed the CT diagnosis of CLO complicated by ischaemia. U or C-sharped of dilated loops, radial distribution of the mesenteric vessels, beaks and whirls suggested CLO, but did not help differentiate CLO from strangulation. CLO is a dynamic entity which may regress or need laparotomy depending on the time and degree of rotation of the incarcerated loops. CT is a reliable imaging modality able to differentiate CLO from strangulation, which is rarely simple and obvious. Detection of ischemic changes in the bowel walls and/or attached mesentery on CT scans imply strangulation highlighting the need for laparotomy; if only signs of CLO are detected, the existence and/or development of strangulation cannot be predicted.