Cecal volvulus. Coronal reformatted CT image and axial contrast-enhanced CT scans
demonstrate a markedly enlarged and dilated air- and fluid-filled cecum (arrow in a and b) extending from the right lower quadrant to the left upper quadrant. Note the abrupt transition between the collapsed, twisted segment of the colon (short arrows in c) and the dilated, obstructed segment (long arrow in c). There is also a subtle whorl of mesenteric vessels (whirl sign) in the right lower quadrant (arrowheads in c) related to torsion of the mesentery caused by the rotated cecum.