Biochemical Markers and MR Imaging Findings as Predictors of Crohn Disease Activity in Patients Scanned by Contrast-enhanced MR Enterography

Rationale and Objectives: To define the best independent predictors for active inflammation in patients with Crohn disease (CD) examined by contrast-enhanced magnetic resonance (MR) enterography. Materials and Methods: Ninety-one patients (47 men and 44 women; aged 39.58 17.1 years) with a diagnosis of CD; CD activity index (CDAI)$150 (n = 19 patients) or <150 (n = 72) underwentMR enterography including T2-weighted half-Fourier acquisition single-shot turbo spin-echo, T2-weighted spectral fat presaturation with inversion recovery, T1-weighted balanced steady-state free precession, and T1-weighted breath-hold resolution isotropic high volume three-dimensional MR imaging sequences before and after administration of gadobenate dimeglumine during arterial (30 seconds), portal venous (70 seconds), and delayed phase (3 and 5 minutes from contrast injection). Two readers analyzed the MR images in consensus. Reference standard was the Crohn’s Disease Endoscopic Index of Severity (CDEIS) with deep mucosal biopsy or the histologic analysis of the surgical specimen in those patients (n = 30) who underwent elective small-bowel resection. Univariate and multivariate logistic regression analyses were performed to assess CDAI, biochemical markers (C-reactive protein and fecal calprotectin levels) and MR imaging findings as potential predictors of inflammatory CD activity. Results: Patients revealed prevalently active (n = 47 patients) or quiescent CD with mural fibrosis (n = 44 patients). The bowel wall T2 hyperintensity (odds ratio [OR], 9.20; 95% confidence interval [CI], 2.71–31.19) and total length of disease (OR, 1.29; 95% CI, 1.11–1.49) were found as the best independent predictors of active CD. CDAI, C-reactive protein, and fecal calprotectin were not found independent predictors of active CD. Conclusions: The bowel wall T2 hyperintensity and the length of the involved bowel tract were predictors of active inflammation in patients with CD examined by contrast-enhanced MR enterography.