Quantitative evaluation of Crohn's disease using dynamic contrast-enhanced MRI in children and young adults.

Objectives: To evaluate the clinical usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in children and young adults with Crohn's disease.

Methods: From August 2017 to October 2018, 30 patients with Crohn's disease (21 males and 9 females; mean age 15.1 ± 2.5 years) underwent DCE-MRI with MRI enterography. We assessed the endoscopic finding, pediatric Crohn's disease activity index (PCDAI), C-reactive protein (CRP) level (mg/dL), Crohn's disease MR index (CDMI) score, and the perfusion parameters of DCE-MRI (K, K, and V) at the ileocecal region between the inactive and active groups based on the histopathologic status.

Results: The active Crohn's disease group showed higher PCDAI, CRP, and CDMI scores than the inactive group (22.2 ± 18.8 vs. 6.3 ± 6.4, p = 0.027; 1.32 ± 1.79 vs. 0.10 ± 0.13, p = 0.005; 7.4 ± 3.9 vs. 4.5 ± 3.0, p = 0.047, respectively). The active Crohn's disease group showed a higher K value than the inactive group (0.31  ±  0.12 vs. 0.16 ±  0.46 min, p = 0.002). Endoscopic finding; PCDAI, CRP, and CDMI scores; and K value were significant parameters in the identification of the active Crohn's disease (p = 0.002, p < 0.001, p = 0.029, p = 0.006, and p < 0.001, respectively). K value was the most significant value for identifying active Crohn's disease in the multivariate logistic regression analysis (p = 0.013).

Conclusion: K value could discriminate between inactive and active Crohn's diseases. K value may have the potential to monitor the pediatric Crohn's disease activity.

Key Points: • With dynamic contrast-enhanced MRI, we can quantitatively monitor the Crohn's disease status in pediatric patients and provide proper management plans to clinicians. • The Kvalue of dynamic contrast-enhanced MRI perfusion parameter, as well as the clinical pediatric Crohn's disease activity index, C-reactive protein level, the endoscopic score, and the Crohn's disease MR index, was higher in the active Crohn's disease than in the inactive group based on the histopathologic status. • The Kvalue among the dynamic contrast-enhanced MRI perfusion parameters was the most significant differentiating parameter for the active Crohn's disease from inactive status among those parameters (p = 0.013).