There is a point of marked narrowing indicative of congenital duodenal atresia depicted here. Interestingly, half of all duodenal atresias occur with Down syndrome, although conversely, few cases of Down syndrome have duodenal atresia. By ultrasound, there is a "double bubble" sign from duodenal enlargement proximal to the atresia accompanying the normal stomach bubble. The normal esophagus, liver, and gallbladder are seen here as well.