Ultrasound evidence of gas in the fissure for ligamentum teres: a sign of perforated duodenal ulcer.

We present a case of confined duodenal ulcer perforation diagnosed on ultrasound. Locules of gas were visible in the fissure for ligamentum teres along with a small amount of free fluid in Morrison's pouch and thickening of the gall bladder wall. To our knowledge, "free" intraperitoneal gas confined to the fissure for ligamentum teres has not previously been reported as an ultrasound finding in perforated duodenal ulcer.