Double bubble sign

PaediatricRadiograph / Antenatal US

Two rounded gas- (or fluid-) filled structures, the distended stomach and proximal duodenum, with little or no distal gas.

What it means

Proximal duodenal obstruction, classically duodenal atresia in the neonate.

Mechanism

Obstruction at the second part of the duodenum distends the stomach and duodenal bulb, which are separated by the pylorus.

Associated conditions

  • Duodenal atresia
  • Annular pancreas
  • Duodenal web or stenosis
  • Malrotation with Ladd bands

Pearls

  • Duodenal atresia is strongly associated with Down syndrome.
  • Distal gas should prompt concern for malrotation with volvulus rather than atresia.

References

  • Radiopaedia: Double bubble sign

For educational use only. This dictionary is a study aid and reference, not a diagnostic tool, and must not be used to guide clinical decisions or patient care. Imaging appearances vary; always correlate with the full clinical picture and confirm with a qualified radiologist.