MRI-DWI effective for detecting colonic inflammation in UC
MedWire News: Study results show that colonography with magnetic resonance imaging combined with diffusion-weighted imaging (MRI-DWI) is effective for detecting colonic inflammation in patients with ulcerative colitis (UC).
Conventional colonoscopy currently represents the “gold standard” for assessing disease activity and inflammation in patients with UC or Crohn’s disease (CD), say researchers, but has the disadvantage of being invasive and requiring colonic preparation.
MRI-DWI has previously been used to detect inflammation successfully in CD patients. It uses differences in the motion of water molecules between tissues to derive image contrast and is therefore noninvasive, does not require any bowel preparation, and is short in duration.
To test the efficacy of MRI-DWI for detection of inflammation in UC and confirm its efficacy in CD, Laurent Peyrin-Biroulet (University Hospital of Nancy-Brabois, Vandoeuvre-lès-Nancy, France) and colleagues recruited 35 patients with UC and 61 with CD to undergo MRI-DWI-colonography. Of these, a corresponding 28 and 40 also underwent endoscopy and were included in the analysis.
A segmental magnetic resonance score (MR-score-S) out of a total score of 30 for UC and 36 for CD was derived from the presence or absence of six radiological signs of inflammation (1 point for each sign) in the rectum, sigmoid, left colon, transverse colon, right colon, and ileum (CD only).
In the UC patients, a MR-score-S of more than 1 was found to detect endoscopic inflammation with a sensitivity and specificity of 89.47% and 86.67%, respectively, and an area under the receiver operating characteristic curve (AUROC) score of 0.92.
A MR-score-S of more than 2 detected endoscopic inflammation in CD patients with a specificity of 84.48%, a sensitivity of 58.33%, and an AUROC score of 0.78.
The odds ratios for accurate prediction of colonic endoscopic inflammation by DWI hyperintensity in UC and CD patients were 13.26 and 2.67, respectively.
Both the MR-score-S and DWI hyperintensity predicted endoscopic colonic inflammation significantly better in UC than CD patients.
“MRI-DWI-colonography without oral or rectal preparation could represent a noninvasive tool in assessing colonic inflammation in inflammatory bowel disease, especially in UC,” conclude Peyrin-Biroulet and colleagues in the journal Gut.
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By Helen Albert