Diffusion-weighted MRI for detecting ileal inflammation in Crohn's

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

Whether diffusion-weighted imaging (DWI)-MRI 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 threshold to differentiate active from non-active lesions, and to assess inter-observer agreement.

The team reported that 31 Crohn's disease patients from the Clermont-Ferrand IBD unit with ileal involvement were consecutively and prospectively included in 2011.

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

The doctors noted that qualitative and quantitative results were compared with conventional MRE including MaRIA score calculation and independent activity predictors.

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

Qualitative analysis of sequences determined sensitivity value as 100%

Alimentary Pharmacology & Therapeutics

The research team observed that results 17 patients had active Crohn's disease as defined by the MaRIA score 7.

DWI hyperintensity was highly correlated with disease activity evaluated using conventional MRE.

The doctors noted that qualitative analysis of sequences determined sensitivity, specificity, positive predictive value and negative predictive value as 100%, 93%, 94%, 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, 82.4% and 100%.

The researchers reported that inter-observer agreement was high with regard to DWI hyperintensity and apparent diffusion coefficient.

Dr Buisson's team concludes, "Diffusion-weighted imaging-MR enterography is a well-tolerated, non-time-consuming and accurate tool for detecting and assessing inflammation in small bowel Crohn's disease."