The whirl sign: a non-specific finding of mesenteric rotation.

The whirl sign has been described as a computed tomography (CT) finding of volvulus of the gut. Six cases are presented with a range of clinical diagnoses (a volvulus, adhesive obstruction with volvulus and previous left hemicolectomy, adhesions alone, transverse colectomy, and right hemicolectomy). All demonstrated a whirl sign. A further case simulating a whirl sign is also presented. We propose that the whirl sign, although a finding highly suggestive of volvulus, can occur in any situation that produces rotation or twisting of bowel and its mesenteric attachment.