Diffusion-weighted magnetic resonance without bowel preparation for detecting colonic inflammation in inflammatory bowel disease.
OBJECTIVE
Magnetic resonance imaging (MRI) enables accurate assessment of inflammatory bowel diseases (IBD), but its main limitation is the need for bowel preparation. Diffusion-weighted imaging is feasible in Crohn's disease. We evaluated the accuracy of MRI in combination with diffusion-weighted imaging (DWI-MRI) without oral or rectal preparation in assessing colonic inflammation in both ulcerative colitis and Crohn's disease.


METHODS
This was an observational study of a single-centre cohort.


METHODS
All patients who underwent DWI-MRI-colonography without bowel preparation between January 2008 and February 2010 in our centre were analysed.


RESULTS
Among the 96 patients (ulcerative colitis=35; Crohn's disease=61) who had DWI-MRI-colonography, 68 had concomitant endoscopy. In ulcerative colitis a segmental magnetic resonance score (MR-score-S) >1 detected endoscopic inflammation with a sensitivity and specificity of 89.47% and 86.67%, respectively (AUROC=0.920, p=0.0001). In the Crohn's disease group, a MR-score-S >2 detected endoscopic inflammation in the colon with a sensitivity and specificity of 58.33% and 84.48%, respectively (AUROC=0.779, p=0.0001). The MR-score-S demonstrated better accuracy for the detection of endoscopic inflammation in the ulcerative colitis group than in the Crohn's disease group (p=0.003). In ulcerative colitis, the proposed total magnetic resonance score (MR-score-T) correlated with the total modified Baron score (r=0.813, p=0.0001) and the Walmsley index (r=0.678, p<0.0001). In Crohn's disease, the MR-score-T correlated with the simplified endoscopic activity score for Crohn's disease (r=0.539, p=0.001) and the Crohn's disease activity index (r=0.367, p=0.004). The DWI hyperintensity was a predictor of colonic endoscopic inflammation in ulcerative colitis (OR=13.26, 95% CI 3.6 to 48.93; AUROC=0.854, p=0.0001) and Crohn's disease (OR=2.67, 95% CI 1.25 to 5.72; AUROC=0.702, p=0.0001). The accuracy of the DWI hyperintensity for detecting colonic inflammation was greater in ulcerative colitis than in Crohn's disease (p=0.004).


CONCLUSIONS
DWI-MRI-colonography without bowel preparation is a reliable tool for detecting colonic inflammation in ulcerative colitis.
Oussalah
Abderrahim
A
Inserm, U954 and Department of Hepato-Gastroenterology, University Hospital of Nancy, Vandoeuvre-lès-Nancy, France.
Laurent
Valérie
V
Bruot
Olivier
O
Bressenot
Aude
A
Bigard
Marc-André
MA
Régent
Denis
D
Peyrin-Biroulet
Laurent
L
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002400:Cathartics; D003093:Colitis, Ulcerative / Q000175:diagnosis*; D003113:Colonoscopy / Q000379:methods; D003424:Crohn Disease / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D055815:Young Adult
D015415:Biomarkers; D002400:Cathartics