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

Abstract

To assess the usefulness of MR colonography (MRC) with a fecal tagging technique and water-based enema in patients with inflammatory bowel disease (IBD). 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 (200ml) at major meals starting 2days before the MRI. After a water enema (2000-2500ml), the MR protocol was carried out, starting with HASTE and true-FISP sequences. Coronal T1w 3D VIBE (2.0mm thick) was obtained before and 60s 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). 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. 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.