Role of quantitative MRI diffusion-weighted imaging (DWI) in detecting lesion activity in patients with Crohn's disease

Aim and objectives: To evaluate the value of diffusion-weighted magnetic resonance imaging ( DWI) in localization of diseased bowel segment and to determine the value of apparent diffusion coefficient ( ADC) to diagnose activity in patients with Crohn's disease. Materials and methods: 30 patients of Crohn's disease and 45 normal persons as a control underwent DWI and ADC maps and the results were compared to the postendoscopic and pathologic post-operative results. Results: On DWI bowel segments with active inflammation revealed higher signal compared to inactive and normal segments. Using ADC, statistical high significance was found between both active and inactive segment values when correlated to normal segment values with P < 0.05. Correlating mean ADC value and range of active and inactive segments, a statistical difference was noted ( P < 0.05). Using 1.65 x 10(-3) mm(2) s(-1) as the cutoff point, the sensitivity of ADC values for differentiating active and inactive bowels was 88.7%, and the specificity was 80%, PPV 89.7%, NPV 79.0%, Kappa 0.65 and P < 0.05. Conclusion: Adding DWI and quantitative ADC value study to MRI imaging is a promising technique for the detection of inflammation in patients with Crohn's disease and differentiating between active and inactive diseased bowel segments. (C) 2015 The Authors. The Egyptian Society of Radiology and Nuclear Medicine. Production and hosting by Elsevier B.V.