Toxic dilatation in Crohn disease with CT correlation.

We describe the CT appearance of toxic dilatation in a patient with Crohn disease. The CT manifestations of this uncommon but important entity have not been previously described. The involved portion of the colon was mildly dilated and demonstrated pseudopolyp formation. Bowel wall thickening in this segment was minimal as expected in toxic dilatation. Intramural gas was identified representing pneumatosis intestinalis, an ominous sign in this condition.