Whirlpool sign - seen when bowel rotates around its mesentery with the vessels and collapsed bowel creating the whirls. It is found in a number of settings including malrotation complicated by midgut volvulus and caecal volvulus. In midgut volvulus the swirl is counter-clockwise on CT (as if viewed from below) and clockwise on US and is analogous to the corkscrew sign seen on barium studies. The above case shows a whirlpool sign in caecal volvulus - click here to scroll through the entire image stack.

Malrotation can cause a very proximal obstruction, it can be easily confused with duodenal atresia, which presents in the same time period as malrotation with volvulus, the x-ray evidence of duodenal atresia can show a “double bubble” sign, which is evidence of a proximal small bowel obstruction or a gasless abdomen

Corkscrew sign - describes the spiral appearance of the distal duodenum and proximal jejunum in the setting of midgut volvulus on contrast studies. In patients with congenital malrotation of the midgut, the distal duodenum and proximal jejunum do not cross the midline and instead pass inferiorly. These loops are predisposed to twist on their shortened mesentery creating the classic corkscrew appearance of midgut volvulus.