Bird beak sign
AbdomenFluoroscopy / CT
Smooth tapering of a lumen to a narrow point, resembling a bird's beak, at the site of narrowing.
What it means
A smoothly tapered obstruction, seen at the gastro-oesophageal junction in achalasia and at the twist point in volvulus.
Mechanism
Functional or mechanical narrowing tapers the barium- or contrast-filled lumen smoothly to a point rather than an abrupt cut-off.
Associated conditions
- Achalasia
- Sigmoid volvulus
- Caecal volvulus
- Gastric volvulus
Pearls
- In achalasia the beak sits at the gastro-oesophageal junction with a dilated proximal oesophagus.
- In volvulus the beak marks the twist and points toward the closed loop.
References
- Radiopaedia: Bird beak 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.