Imaging to detect and assess ileal inflammation in Crohn's disease

A study published ahead of print in the Alimentary Pharmacology & Therapeutics examines diffusion-weighted magnetic resonance imaging for detecting and assessing ileal inflammation in Crohn's disease.

Whether diffusion-weighted imaging is of value in detecting and assessing inflammation of ileal Crohn's disease remains poorly investigated.

Dr Buisson and colleagues compared DWI-MR enterography with conventional MRE in estimating inflammation in small bowel Crohn's disease, to determine an apparent diffusion coefficient (ADC) threshold to differentiate active from non-active lesions and to assess inter-observer agreement.

The team evaluated Crohn's disease patients from the Clermont-Ferrand IBD unit with ileal involvement in 2011.

Qualitative analysis of DW sequences determined sensitivity as 100%

Alimentary Pharmacology & Therapeutics

All patients underwent diffusion-weighted imaging to detect the digestive segment with the most severe lesions, which was then used to calculate the apparent diffusion coefficient.

The research team compared qualitative and quantitative results with conventional MRE including MaRIA score calculation and independent activity predictors.

Each examination was interpreted independently by two radiologists blinded for clinical assessment.

The doctors reported that 17 patients had active Crohn's disease as defined by the MaRIA score.

The team found that diffusion-weighted imaging hyperintensity was highly correlated with disease activity, evaluated using conventional MRE.

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 apparent diffusion coefficient yielded sensitivity and specificity values of, respectively, 82% and 100%.

Dr Buisson's team concluded, "Inter-observer agreement was high with regard to diffusion-weighted imaging hyperintensity and  apparent diffusion coefficient."

"Whether diffusion-weighted imaging enterography is a well-tolerated, non-time-consuming and accurate tool for detecting and assessing inflammation in small bowel Crohn's disease."