Is it Crohn's disease or intestinal tuberculosis? CT analysis.

A computed tomographic (CT) analysis of 36 patients with differential diagnosis of intestinal tuberculosis (IT) or Crohn's disease (CD) in barium gastrointestinal studies was undertaken to identify distinguishing bowel wall or mesenteric features which could provide a radiological definitive diagnosis. Final diagnoses obtained in 32 cases were tuberculosis (N = 18), CD (N = 9), carcinoid (N = 2), chronic appendicitis (N = 2) and bowel infarction (N = 1). In IT, the bowel wall changes were varied: absence of wall thickening (N = 6), minimal asymmetric wall thickening with and without mucosal tethering (N = 8), minimal symmetric wall thickening often with mild peritonitis (N = 3), exophytic mass encircling bowel lumen (N = 4). Mural stratification (target sign) was not found. CD showed concentric or symmetrical wall thickening ranging from 0.6 to 1.5 mm and mural stratification occurred in about a half of the cases. Lymphadenopathy was the commonest associated feature in both but in IT, the nodes were larger and a third had necrotic centers. Displacement of bowel loops was more often due to enlarged lymphadenopathy in IT while in CD it was frequently due to fibrofatty change. CT was able to provide the correct diagnosis in 26 out of these 32 (81%) cases of indeterminate barium studies. CT is recommended when barium gastrointestinal studies are unable to differentiate between intestinal tuberculosis and Crohn's disease.