Dynamic contrast enhanced magnetic resonance imaging of the terminal ileum: differentiation of activity of Crohn's disease

Abstract

Aim: To prospectively investigate a new high resolution MRI technique for dynamic evaluation of the enhancement kinetics of bowel parietal layers and to correlate it with CDAI, CRP, endoscopic activity and histologic features.

Methods: About 16 consecutive patients with proven diagnosis of CD underwent ileocolonoscopy with biopsy and serial bowel dynamic contrasted-MRI (D-CE-MRI) evaluated in blind fashion. Quantitative analysis of bowel wall enhancement kinetics was performed basing on signal to noise ratio (SNR) of inner parietal layers (Mucosa-Submucosa, M-SM) and outer parietal layers (Muscular-Serosa, Ms-S). Disease activity was defined by CDAI > 150, serum CRP > 5 mg/dL and histologic results.

Results: About 9 patients showed a layered enhancement of bowel wall (8 active, 1 inactive), whereas inactive (7 cases) group presented a homogeneous pattern. In active patients we found a significant difference in parietal layered enhancement curves (M-SM vs. Ms-S, P < 0.03) not observed in inactive disease and controls (intra-group analysis). M-SM and Ms-S enhanced curves in clinically active patients were significantly different respect to those of patients with inactive CD (P < 0.001) (inter-group analysis). Parietal D-CE-MRI pattern well correlated with histologic features (r = 0.8; P < 0.001, Spearman test).

Conclusions: D-CE-MRI can be a useful tool for clinical follow-up and in the treatment strategies in CD patients.