Quantitative Analysis of Dynamic Contrast Enhanced MRI for Assessment of Bowel Inflammation in Crohn's Disease: Pilot Study

Abstract

The aim of this study was to evaluate the feasibility of quantitative analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data in the detection of bowel inflammation in patients with Crohn's disease. Eleven patients who underwent magnetic resonance enterography for known or suspected Crohn's disease and had colonoscopy or surgery within 4 weeks of imaging were included in this study. DCE-MRI data were acquired using a 1.5-T scanner with temporal resolution of 5 to 12 seconds for approximately 5 to 7 minutes. A two-compartment pharmacokinetic model was used to analyze the data to obtain the volume transfer constant (K(trans)) and the extravascular extracellular space (v(e)). Additionally, semiquantitative parameters were derived using an empirical mathematical model to fit the contrast concentration curves. Endoscopic, surgical, and pathologic results were compared to the MRI data. Receiver-operating characteristic analysis was performed to compare the diagnostic accuracy of the parameters in the task of distinguishing normal tissue from inflammation. A total of 51 bowel segments (19 with inflammation, 32 normal) were included in the analyses. Inflamed bowel segments had faster K(trans) values, larger v(e) values, increased contrast uptake, larger initial areas under the contrast concentration curve, and steeper initial enhancement slopes than normal bowel segments (P < .05). The areas under the receiver-operating characteristic curve for these parameters ranged from 0.70 to 0.86. These preliminary results demonstrate that the quantitative analysis of DCE-MRI data is possible for the assessment of bowel inflammation in patients with Crohn's disease. Future studies need be performed on larger numbers of patients to correlate the severity and type of inflammation with kinetic parameters.