The diagnostic role of abdominal CT imaging findings in adults intussusception: focused on the vascular compromise

Intussusception is defined as telescoping of one segment of the gastrointestinal tract into an adjacent one. Unlike that in children, adult intussusception is a relatively rare condition. More than 90% of patients with adult intussusception have been reported to have an organic cause, with benign or malignant tumors for accounting for approximately 65% of the cases. In general, the diagnosis is easily made by means of computed tomography (CT) or magnetic resonance (MR) imaging. The imaging appearance of a bowel-within-bowel configuration with or without contained fat and mesenteric vessels, is pathognomonic. As the intussusceptum enters into the intussuscipiens, the mesentery is carried forward and trapped between the overlapping layers of bowel. The twisting or severe constriction of the mesenteric vessels may result in vascular compromise with subsequent edematous thickening of the involved bowel. In these circumstances, ischemic necrosis may develop if timely intervention is not undertaken. Therefore, determination of the presence or absence of intestinal necrosis in intussusception is important in patient management. On CT, the presence of well-known diagnostic CT criteria for strangulated obstruction (especially severe engorgement or twisting of the mesenteric vessels) as well as evidence of loss of the layered pattern, accumulation of extraluminal fluid collection, and bowel perforation, may suggest the diagnosis of intestinal necrosis. CT and MR imaging are limited in determining the primary disease causing intussusception. However, CT and MR provide excellent pre-operative evaluation, including the possible extension and/or dissemination of a malignant tumor. CT and MR imaging may also be useful in suggesting the presence of vascular compromise.