MR colonography with a fecal tagging technique and water-based enema for the assessment of inflammatory bowel disease.

PURPOSE: To assess the usefulness of MR colonography (MRC) with a fecal tagging technique and water-based enema in patients with inflammatory bowel disease (IBD).

MATERIALS AND METHODS: Twenty-two patients with suspected or known IBD underwent MRC with a 1.5-T MR system (Siemens Symphony) using a phased-array coil. A fecal tagging technique was performed by oral administration of dense barium sulfate (200 ml) at major meals starting 2 days before the MRI. After a water enema (2000-2500 ml), the MR protocol was carried out, starting with HASTE and true-FISP sequences. Coronal T1w 3D VIBE (2.0 mm thick) was obtained before and 60 s after intravenous administration of Gd chelate. MR images were evaluated by consensus agreement of two observers in terms of image quality and by searching for bowel abnormalities. MRC findings were correlated with our gold standard-conventional colonoscopy (incomplete in 6/22 patients) with histopathological analysis, and surgery (performed in 8/22 subjects).

RESULTS: The MR imaging protocol was completed in all of the investigated subjects. In terms of image quality, 128 out of 132 colon segments (97 %) were considered diagnostic on MR examinations by the two reviewers; signs of bowel inflammation were identified in 74 and 72 % of colon segments of patients with ulcerative colitis (n = 6) and Crohn's disease (n = 15), respectively. In 13/15 patients with Crohn's disease, involvement of both the large and small bowel was demonstrated on MR imaging; perianal abscesses and fistulas were also identified in 2 and 3 of these patients, respectively. In one patient with normal MRC, a diagnosis of IBD could not be confirmed.

CONCLUSION: MRC with a fecal tagging technique and water-based enema is a promising minimally invasive technique for evaluating the bowel in patients with a suspected or established diagnosis of IBD.