Validity of plain films in intussusception

The aim of this study was to re-evaluate the specificity of plain film findings in intussusception. The plain film findings in 80 cases of proven intussusception were reviewed. Findings documented were: (1) presence or absence of small bowel obstruction, (2) paucity of right lower quadrant gas, (3) presence of an intracolonic mass, (4) presence of a rim or target sign, and (5) presence of the classic triad of intestinal obstruction, intracolonic mass, and paucity of right lower quadrant gas. Intestinal obstruction was present in 54% of patients. In 19 patients (24%) the abdominal films were completely normal. Paucity of right lower quadrant gas was seen in 10% of patients, while specific findings of a mass or a target (rim) sign were seen in 29% of patients. The classic triad of an intracolonic mass, obstruction, and paucity of gas in the right lower quadrant occurred in only 1 patient (1%). Plain films of the abdomen were diagnostic of intussusception in only 29% of cases. A completely normal gas pattern was seen in one-quarter of our patients. This being the case, most patients with suspected intussusception will require further imaging, either by ultrasound or contrast enema. In our institution we favor the ultrasound study.