Intussusception: the sonographic diagnosis and its clinical value.

During the past four years in our hospital, real-time sonographic examinations were performed prior to barium enema reductions in 48 proven intussusception cases. Four major sonographic findings were noted. First, a length of target configuration consisting of two rings of low echogenicity separated by an intermediate hyperechoic ring was seen on the cross-sectional image of the intussuscepted bowel. Second, a doughnut configuration consisting of a hypoechoic rim and a dense central echogenic core was noted on the cross section near the apex of the intussusceptum. Third, no demonstrable movement or change was observed in the target or doughnut configuration. Fourth, all of the exterior sonolucent rims of the target were thicker than 0.6 cm. Operative reductions were necessary in all 13 cases whose exterior rims were thicker than 1.6 cm. On the contrary, only 15 of the remaining 35 cases whose exterior rims were between 0.6 and 1.5 cm needed surgical management (p = 0.0033, Fisher's exact test).