Reversible portal venous gas in hypertrophic pyloric stenosis: detection by ultrasound.

Portal venous gas typically is described as a feature of NEC and in many cases is associated with pneu ~ matosis cystoides intestinalis. Radiographic findings of both phenomena also may be observed in connection with other conditions such as Hirschspnmg's disease, collagen vascular diseases, or intestinal obstruction with massive bowel distention) These radiologic symptoms may be detected with the help of imaging methods such as plain film, ultrasonography and computed tomography. Alone among these imaging techniques, sonography is a noninva-