July 18, 2009

Double Bubble Sign

Supine abdominal radiograph of a newborn presenting with billous vomiting shows a distended stomach and duodenal air bubbles "double bubble" sign. There is no gas distal to the duodenal bubble. Radiopaque materials overlying the right pelvis are due to soiled diaper.

Double Bubble Sign
  • Radiographic signs describing two air-filled structures in the upper abdomen with little or no air distally
  • Can be reproduced in upper GI study or ultrasound
  • Left-sided bubble = stomach
  • Right-sided bubble (usually right of midline) = duodenum
  • Most common cause = duodenal atresia
Differential Diagnoses
  • Intrinsic cause: duodenal atresia, duodenal stenosis, duodenal web
  • Extrinsic cause: annular pancreas, malrotation with obstruction produced by midgut volvulus or by Ladd bands
Main Concern
  • Must be differentiated from 'malrotation with obstruction (midgut volvulus)' because this condition requires urgent surgery
  • Suspect midgut volvulus if stomach is distended but duodenum is normal or only slightly dilated

Reference:
Traubici J. The double bubble sign. Radiology 2001;220:463-464.

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