Multiple concentric ring sign in the ultrasonographic diagnosis of intussusception.

Gray scale ultrasound examination of two patients with abdominal space-occupying lesions demonstrated characteristic ring shadows on longitudinal scans. In one case a multiple concentric ring shadow resulted from an ileocolic intussusception, and in the other a "bull's eye" image was due to an infiltrating carcinoma of the pyloric antrum. A study of these patients confirms the suspicion [1] that there is a characteristic ultrasonic appearance of intussusception in bowel loops.