Diffusion-weighted magnetic resonance imaging for detecting and assessing ileal inflammation in Crohn's disease
Article first published online: 7 JAN 2013
© 2013 Blackwell Publishing Ltd
Alimentary Pharmacology & Therapeutics
Volume 37, Issue 5, pages 537–545, March 2013
How to Cite
Aliment Pharmacol Ther 2013; 37: 537–545
- Issue published online: 1 FEB 2013
- Article first published online: 7 JAN 2013
- Manuscript Accepted: 12 DEC 2012
- Manuscript Revised: 10 DEC 2012
- Manuscript Revised: 29 NOV 2012
- Manuscript Received: 15 NOV 2012
Vol. 37, Issue 10, 1031, Article first published online: 17 APR 2013
Whether diffusion-weighted imaging (DWI)-MRI is of value in detecting and assessing inflammation of ileal Crohn's disease (CD) remains poorly investigated.
To compare DWI-MR enterography (MRE) with conventional MRE in estimating inflammation in small bowel CD, to determine an apparent diffusion coefficient (ADC) threshold to differentiate active from non-active lesions and to assess inter-observer agreement.
Thirty-one CD patients from the Clermont-Ferrand IBD unit with ileal involvement were consecutively and prospectively included between April and June 2011. All patients underwent DWI-MRI to detect the digestive segment with the most severe lesions, which was then used to calculate the ADC. Qualitative and quantitative results were compared with conventional MRE including MaRIA (Magnetic Resonance Index of Activity) score calculation and independent activity predictors (wall thickening, oedema, ulcers). Each examination was interpreted independently by two radiologists blinded for clinical assessment.
Seventeen patients (54.8%) had active CD as defined by the MaRIA score ≥7. DWI hyperintensity was highly correlated with disease activity evaluated using conventional MRE (P = 0.001). Qualitative analysis of DW sequences determined sensitivity, specificity, positive predictive value and negative predictive value as 100%, 92.9%, 94.4% and 100% respectively. Quantitative analysis using a cut-off of 1.6 × 10−3 mm²/s for ADC yielded sensitivity and specificity values of, respectively, 82.4% and 100%. Inter-observer agreement was high with regard to DWI hyperintensity (κ = 0.69, accuracy rate = 85.7%) and ADC (correlation = 0.74, P < 0.001, and concordance = 0.71, P < 0.001).
DWI-MR enterography is a well-tolerated, non-time-consuming and accurate tool for detecting and assessing inflammation in small bowel Crohn's disease.