Can Dynamic Contrast-Enhanced MRI (DCE-MRI) and Diffusion-Weighted MRI (DW-MRI) Evaluate Inflammation Disease: A Preliminary Study of Crohn's Disease

The aim of the study was to investigate diagnosis efficacy of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in Crohn's disease (CD). To find out the correlations between functional MRI parameters including K(trans), K(ep), V(e), V(p), and apparent diffusion coefficient (ADC) with a serologic biomarker. The relationships between pharmacokinetic parameters and ADC were also studied. Thirty-two patients with CD (22 men, 10 women; mean age: 30.5 years) and 18 healthy volunteers without any inflammatory disease (10 men, 8 women; mean age, 34.11 years) were enrolled into this approved prospective study. Pearson analysis was used to evaluate the correlation between K(trans), K(ep), V(e), V(p), and C-reactive protein (CRP), ADC, and CRP respectively. The diagnostic efficacy of the functional MRI parameters in terms of sensitivity and specificity were analyzed by receiver operating characteristic (ROC) curve analyses. Optimal cut-off values of each functional MRI parameters for differentiation of inflammatory from normal bowel were determined according to the Youden criterion. Mean value of K(trans) in the CD group was significantly higher than that of normal control group. Similar results were observed for K(ep) and V(e). On the contrary, the ADC value was lower in the CD group than that in the control group. K(trans) and V(e) were shown to be correlated with CRP (r = 0.725, P < 0.001; r = 0.533, P = 0.002), meanwhile ADC showed negative correlation with CRP (r = −0.630, P < 0.001). There were negative correlations between the pharmacokinetic parameters and ADC, such as K(trans) to ADC (r = −0.856, P < 0.001), and V(e) to ADC (r = −0.451, P = 0.01). The area under the curve (AUC) was 0.994 for K(trans) (P < 0.001), 0.905 for ADC (P < 0.001), 0.806 for V(e) (P < 0.001), and 0.764 for K(ep) (P = 0.002). The cut-off point of the K(trans) was found to be 0.931 min(–1). This value provided the best trade-off between sensitivity (93.8%) and specificity (100%). The best cut-off point of ADC was 1.11 × 10(–3) mm(2)/s. At this level, sensitivity was 100% and specificity was 68.8%. DCE-MRI and DW-MRI were helpful in the diagnosis of CD. Quantitative MRI parameters could be used to assess the severity of inflammation. The relationships between pharmacokinetic parameters (K(trans) and V(e)) and ADC reflected microstructure and microcirculation of CD to some extent.