Adult Intestinal Intussusception: CT Appearances and Identification of a Causative Lead Point1

The widespread application of computed tomography (CT) in different clinical situations has increased the detection of intussusception, particularly non–lead point intussusception, which tends to be transient. Consequently, determining the clinical significance of intussusception seen at CT poses a diagnostic challenge. Patients with intussusception may or may not be symptomatic, and symptoms can be acute, intermittent, or chronic, making clinical diagnosis difficult. In most cases, radiologists can readily make the correct diagnosis of intestinal intussusception by noting the typical bowel-within-bowel appearance at abdominal CT. However, the CT findings that help differentiate between lead point and non–lead point intussusception have not been well studied. Nevertheless, although there is considerable overlap of CT findings, when a lead mass is seen at CT as a separate and distinct entity vis-à -vis edematous bowel, it can be considered a reliable indicator of a lead point intussusception. Differentiating between lead point and non–lead point intussusception is important in determining the appropriate treatment and has the potential to reduce the prevalence of unnecessary surgery. © RSNA, 2006