IS case 530: Adult intestinal malrotation
Imaging Sciences URMC 2010
Publication Date: 2010-09-11
Congenital intestinal malrotation usually presents within the first few weeks after birth, however, the condition may remain asymptomatic for life and be found as an incidental finding on CT scan performed for other reasons. Intestinal malrotation is defined as deviation from the normal 270 degree counterclockwise rotation of the midgut during embryologic development. CT findings of intestinal malrotation include deviation from normal relationship of the superior mesenteric artery and superior mesenteric vein. Normally, the superior mesenteric vein lies to the right of the superior mesenteric artery. In malrotation, there may be an inversion of the two vessels, or they may assume a vertical relationship, as seen in this case.
Another finding in malrotation is malposition of the right colon and cecum. This is important because a patient may present with appendicitis, but with left-sided symptoms. More importantly, the rules used in pediatric radiology also apply to adult cases; that is, the duodenal-jejunal junction must cross the midline and lie below the level of the duodenal bulb. An abnormally positioned junction also supports the diagnosis of intestinal malrotation.
- Pickhardt PJ, Bhalla S. Intestinal malrotation in adolescents and adults: spectrum of clinical and imaging features. AJR Am J Roentgenol. 2002 Dec;179(6):1429-35. PMID: 12438031