CT of bowel and mesenteric trauma in children.

Although most traumatic abdominal injuries in children are treated with conservative nonsurgical management, traumatic perforation or infarction of the gastrointestinal tract still necessitates surgical management. It is imperative to recognize the often subtle computed tomographic (CT) findings of bowel or mesenteric trauma in children. Pediatric patients with bowel perforation or infarction due to trauma usually demonstrate multiple abnormalities at CT. A specific history of lap belt injury, bicycle handlebar injury, or child abuse with an abdominal injury should heighten suspicion for a bowel injury. CT findings in children with bowel or mesenteric trauma include free intraperitoneal air, free retroperitoneal air, extraluminal oral contrast material, free intraperitoneal fluid, bowel wall defect, bowel wall thickening, mesenteric stranding, fluid at the mesenteric root, focal hematoma, active hemorrhage, and mesenteric pseudoaneurysm. Some findings, such as free intraperitoneal air and focal bowel wall thickening, are associated with a strong likelihood of a bowel injury that requires surgical repair. Other findings, such as free intraperitoneal fluid, mesenteric stranding, fluid at the mesenteric root, and focal hematoma, are less specific for an injury that requires surgical repair. The hypoperfusion complex can usually be differentiated from a traumatic bowel injury; however, in some patients the imaging findings overlap.