CT of intussusception in the pediatric patient: diagnosis and pitfalls.

Intussusception in the pediatric patient may have a varied clinical presentation depending on its location, presence of lead point, intermittent occurrence, or underlying systemic disease. Computed tomography (CT) may be used at times in the evaluation of children with complicated presentations. The purpose of this investigation was to review the findings of CT images obtained in children with intussusception. Five patients with intussusception were diagnosed by CT at our institution between 1989 and 1994. An intraluminal mass was found in all patients. Intraluminal eccentrically located fat, as well as the target sign of alternating layers of high and low attenuation, was seen in most patients. In patients with a more long-standing process, fluid-distended loops, inflammation, and loss of tissue planes were seen and corresponded with necrosis and areas of nonviable bowel found at surgery. Finally, potential pitfalls with the layered or target appearance are discussed in the form of two patients who were initially felt to have intussusception at CT, but in whom the target appearance was later found to be due to other processes.