Fig. 1

a. The cross section of abdominal CT shows the typical bowel-within-bowel sign suggestive of duodenal intussusception into the jejunum (green circle). The intestinal wall of the head was thickened. The degree of strengthening was slightly reduced. Lumpy contents can be seen in the duodenal cavity. b. The coronal section of the CT scan shows the intussusception of duodenum into the jejunum (green circle) and the descending part of duodenum (blue circle) c. The sagittal section of the CT scan shows the intussusception (green circle) and its positional relation with superior mesenteric artery (red arrow)