Corkscrew sign | Radiology Signs

Answer:

The corkscrew sign occurs due to midgut volvulus resulting from intestinal malrotation, an abnormal rotation of the gut during embryological development. This malrotation leads to a narrow mesenteric root, predisposing the small intestine and proximal jejunum to twist around the superior mesenteric artery (SMA). This volvulus causes a spiral or twisted appearance of the duodenum and jejunum on imaging, seen as a corkscrew-shaped curve. Clinically, this can cause intestinal obstruction, ischemia, and necrosis, most commonly presenting in infants and children.

Why is it called so?

The term “corkscrew sign” describes the characteristic spiral or twisted shape of the duodenum and proximal jejunum loops seen on UGI fluoroscopic studies. The imaging resembles the helical form of a corkscrew tool used to remove corks from bottles.

Pathophysiology

During embryogenesis, failure of the midgut to properly rotate results in malposition of intestinal segments and a shortened mesenteric attachment. This narrow mesenteric pedicle allows the small intestine to twist (volvulus) around the SMA. The twisting impairs venous drainage first, leading to venous congestion and increased tissue pressure, which subsequently compromises arterial blood flow, potentially causing ischemia and necrosis. The torsion of the bowel loops creates the spiral configuration responsible for the corkscrew appearance on imaging.

Alternative names:

None specifically for corkscrew sign, but related imaging findings include the “whirlpool sign” seen on ultrasound or CT, describing the swirling of mesenteric vessels around the SMA in midgut volvulus.

Other associated named signs:

• Whirlpool sign (color Doppler ultrasound/CT imaging of mesenteric vessel twisting)
• Abnormal position of duodenojejunal junction (ligament of Treitz) on UGI studies