Background: We aimed to determine the utility of magnetic resonance imaging (MRI) compared with small bowel follow-through (SBFT) in the assessment of known Crohn's disease.
Methods: Subjects, over age 18 yr who were to undergo SBFT investigations to assess for complications or extent of Crohn's disease were eligible. SBFT was performed by a single radiologist (IB), and within 4 wk MRI was performed by a single radiologist (HG) who was blinded to the SBFT results. For MRI, oral contrast was 2% barium sulfate (1,350 mL). After unenhanced T1 weighted images and single shot fast spin echo T2 imaging, intravenous (IV) glucagon and gadolinium were given. Fast multiplanar spoiled-gradient recalled T1 coronal sequences were obtained followed by abdominal and pelvic axial images. MRI and SBFT were compared for extent of disease, presence of complications, and for identification of extraintestinal disease.
Results: Paired studies were undertaken within a mean of 22 days in 30 subjects. Ten studies were normal by both modalities and 8 studies showed similar extent of Crohn's disease. SBFT revealed additional information in 4, including a stricture in 1 and ileosigmoid fistulas in 2. MRI provided enhanced information in 8, including identifying active inflammation in strictured areas based on wall enhancement patterns, vasa recta changes, and lymphadenopathy.
Conclusions: On the basis of cost and accessibility, SBFT may still be a first line procedure of choice in some centers without MRI, but MRI's advantages of no radiation and the potential to identify active inflammation in strictured areas, extraintestinal, and colorectal disease make it an attractive alternative.