The ultrasound appearances of intramural bowel gas: the bright ring appearance and the effervescent bowel. A report of three cases.

Bowel necrosis is a serious condition with a very high mortality rate. The earlier the diagnosis is made, the better chance for survival. Ultrasound is a primary imaging technique in the diagnosis of the acute abdomen. Three cases are presented in which bowel wall gas could be demonstrated on ultrasound. In all cases there was computed tomographic and either operative or post-mortem correlation. In each case there was a "bright ring" appearance of the affected bowel when the ultrasound examination was carried out in transverse section. In one case, small bubbles were seen arising from the deep surface of the bowel.