Coffee bean sign, steel pan sign and whirl sign in sigmoid volvulus.

A 66-year-old man presented with abdominal distension. A plain radiograph showed the coffee bean sign, suggesting sigmoid volvulus (SV). The CT scans disclosed the steel pan sign, the whirl sign, and the beak-shaped transition point, confirming SV. He improved with colonoscopic decompression and detorsion. Characteristic radiographic signs of SV are briefly discussed.