Impact of gadolinium‐based contrast agent in the assessment of Crohn's disease activity: Is contrast agent injection necessary?

Abstract

Purpose To determine whether magnetic resonance enterography (MRE) performed without intravenous contrast injection is diagnostically noninferior to conventional contrast‐enhanced MRE (CE‐MRE) in patients with Crohn's disease (CD). Materials and Methods This was an Institutional Review Board (IRB)‐approved retrospective study. Ninety‐six patients (52 male and 44 female; 47.18 years ± 13.6) with a diagnosis of CD underwent MRE at 1.5T including T 2 ‐weighted single‐shot turbo‐spin‐echo, T 2 ‐weighted spectral fat presaturation with inversion recovery (SPAIR), T 1 ‐weighted balanced fast‐field‐echo MR sequences, and CE‐MRE consisting in T 1 ‐weighted breath‐hold THRIVE 3D MRI sequences after administration of gadobenate dimeglumine (0.2 mL/kg of body weight). Unenhanced MRE, CE‐MRE, and unenhanced MRE plus CE‐MRE were reviewed in separate sessions with blinding by two readers in consensus, and subsequently by two other readers independently considering a subgroup of 20 patients. Crohn's Disease Endoscopic Index of Severity (CDEIS) and/or histologic analysis of the surgical specimen were considered as reference standards for the assessment of inflammatory activity. Results Patients revealed prevalently active ( n = 55 patients) or quiescent CD ( n = 41 patients). The agreement between unenhanced MRE vs. CE‐MRE in interpreting active bowel inflammation was 96% (123/128 bowel segments; one‐sided 95% confidence interval [CI], >94.4%). Unenhanced MRE vs. CE‐MRE vs. unenhanced MRE plus CE‐MRE revealed a diagnostic accuracy of 93% [90/96] vs. 92% [88/96] vs. 97% [93/96] ( P > 0.05) in the diagnosis of active CD. Interreader agreement was very good for all variables (κ value = 0.8–0.9) except for the measurement of the length of disease (κ value = 0.45). Conclusion Unenhanced MRE was noninferior to CE‐MRE in diagnosing active inflammation in patients with CD. J. MAGN. RESON. IMAGING 2016;43:688–697.