Which imaging finding is characteristic of duodenal atresia?

The characteristic imaging finding associated with duodenal atresia is the double bubble sign. This sign is seen on an abdominal X-ray and represents the presence of two gas-filled structures: the stomach and proximal duodenum, with the distal duodenum being obstructed and not containing any gas. This appearance is due to the blockage preventing continuity in the intestinal tract, resulting in dilation of the proximal segments.

In the context of duodenal atresia, the double bubble sign stands out because it specifically illustrates the absence of gas beyond the second bubble, which differentiates it from other obstructive conditions. The presence of gas in only two areas (the stomach and the proximal duodenum) serves as a diagnostic indicator of this condition.

The single bubble sign is typically associated with conditions affecting the stomach alone, and a gasless abdomen would imply that there is no air in the gastrointestinal tract, which is not consistent with the obstruction seen in duodenal atresia. Meanwhile, the triple bubble sign often indicates an obstruction further down the intestines, such as with jejunal atresia, not the obstruction at the level of the duodenum seen in this disorder. Therefore, the double bubble sign is the most indicative imaging finding for