Quantitative assessment of Crohn's disease activity by means of CE-MRI

Purpose: To report our experience using dynamic MRI after gadolinium injection to assess the inflammatory activity of Crohn’s disease in a population of adults and children. Material and Methods: We studied 30 patients with histologically proven Crohn’s disease, who had MRI (1.5T GE unit) using a phased array coil. Polyethylene glycole solution oral contrast agent (10ml/Kg) was administered. Our study included the acquisition of T2-weighted SSFSE half Fourier sequences and Fast SPGR T1-weighted fat saturated sequences before and after intravenous gadolinium administration (0,01mmol/Kg); the acquisition was repeated 6 times. We measured signal intensity of the normal and pathologic intestinal wall by means of ROI evaluation. We performed time to signal intensity correlation to assess dynamic CE percentage.We compared this score with Crohn Disease Activity Index (CDAI). Results: We observed in terminal ileum intestinal wall pathological thickening in 27 patients. MRI showed early and high CE between 140% and 310% (mean 210) in 22 patients in clinical acute phase of disease (15 pt) and in reactivation phase (7 pt). We observed 8 patients in post-therapy remission phase. After maximum contrast uptake, we observed a plateau phase in 22/30 cases for the total duration of measurement. A significant correlation existed between the peak of contrast uptake and CDAI (r = 0,017982 p=0,01). Conclusion: This data showed dynamic CE-MRI enables to quantify the inflammatory activity of Crohn’s disease. Therefore we propose CE-MRI in the follow up of patients with Crohn’s disease