Every single imaging finding that can be disclosed on conventional and MR enteroclysis was correlated with the Crohn's disease activity index (CDAI). Nineteen consecutive patients with Crohn's disease underwent colon endoscopy and both conventional and MR enteroclysis examinations. Seventeen MR imaging findings and seven conventional enteroclysis findings were ranked on a four-point grading scale and correlated with CDAI, with a value of 150 considered as the threshold for disease activity. Six patients had active disease in the colon according to colon endoscopy. In the remaining 13 patients, the presence of deep ulcers ( P=0.002), small bowel wall thickening ( P=0.022) and gadolinium enhancement of mesenteric lymph nodes ( P=0.014) identified on MR enteroclysis images were strongly correlated to disease activity. The product of deep ulcers and enhancement of lymph node ranks identified on MR enteroclysis were the optimum combination for discriminating active from non-active disease ( F-test: 55.95, P<0.001). Additionally, the ranking of deep ulcers on conventional enteroclysis provided statistically significant differences between active and non-active patients ( F-test: 14.12, P=0.004). Abnormalities strongly suggestive of active Crohn's disease can be disclosed on MR enteroclysis examinations and may provide pictorial information for local inflammatory activity.