Fig. 2.

Contrast-enhanced CT scans of the abdomen demonstrating volvulus of the transverse colon. Axial scans (A-C) show an abrupt caliber change (“beak sign,” red arrows, commonly seen in many types of mechanical ileum) representing the site of the occlusion, and proximal air-fluid level (yellow arrows). Coronal view (B), obtained with multiplanar reconstructions (MPR), demonstrates the same loop twisting around the long axis of its meso (“whirl sign,” red circles); most of the right colon is displaced medially, as well as jejunal loops, due to the partial involvement of the root of the mesentery. Significant right colic dilatation with atony is present; the caliber of the caecum measures more than 17 cm and an evident air-fluid level is identified (yellow arrows).