Spiral CT demonstration of hypervascularity in Crohn disease: “vascular jejunization of the ileum” or the “comb sign”

Abstract

To report spiral CT imaging features of the vascular alterations observed in active, early, or recurrent Crohn disease of the small bowel and colon. Spiral CT examinations of the abdomen and pelvis following oral and intravenous contrast were performed in two cases of active Crohn disease. Spiral CT features of hypervascularity involving the mesenteric vessels of affected segments of bowel include vascular dilatation, tortuosity, and conspicuous prominence and wide spacing of the vasa recta (the “comb” sign). This is attributed to the factors of increased flow and the fibrofatty proliferation in the mesentery and serosa of the affected bowel. Clinical application of these observations may enhance the diagnosis of Crohn disease presenting initially or as an acute recurrence in the differential diagnosis from other conditions.