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Whirl sign

AbdomenCT

The mesenteric vessels and bowel swirl around the superior mesenteric artery, creating a whirlpool of twisted structures.

What it means

Midgut volvulus, usually in the setting of intestinal malrotation.

Mechanism

The bowel and its mesentery rotate around a narrow mesenteric pedicle, wrapping the superior mesenteric vein and vessels around the artery.

Associated conditions

  • Midgut volvulus
  • Intestinal malrotation
  • Small bowel volvulus
  • Internal hernia

Pearls

  • An inverted superior mesenteric artery and vein relationship supports malrotation.
  • Midgut volvulus is a surgical emergency because of the risk of bowel ischaemia.

References

  • Radiopaedia: Whirl sign (midgut volvulus)

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.