Multiparametric MRI for Staging of Bowel Inflammatory Activity in Crohn's Disease with MUSE-IVIM and DCE-MRI: A Preliminary Study.

Rationale And Objectives: To investigate if the combination of multishot diffusion imaging-based multiplexed sensitivity encoding intravoxel incoherent motion (MUSE-IVIM) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is feasible for staging Crohn's disease (CD) activity.

Materials And Methods: A total of 65 CD patients were enrolled and analyzed in this retrospective study. The simplified endoscopic score for Crohn's disease (SES-CD) and magnetic resonance index of activity (MaRIA) were used as the reference. The MUSE-IVIM and DCE-MRI data were acquired at 3.0-T MRI scanner and processed by two radiologists. Three MUSE-IVIM parameters: fast apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (ADC), and the fractional perfusion (Fraction of ADC), as well as four DCE-MRI parameters: volume transfer constant (K), rate constant (K), extravascular extracellular volume fraction (V), and plasma volume fraction (V) were generated. Intraclass correlation coefficient (ICC), non-parametric test (Kruskal-Wallis H and Mann-Whitney U), logistic regression, receiver operating characteristic analysis, Delong test, and Spearman's correlation test were performed.

Results: According to SES-CD, 116 ileocolonic segments with CD lesions were identified as: inactive, mild, and moderate to severe. With multivariable logistic regression analysis, ADC (p < 0.001), Fraction of ADC (p = 0.005), K (p < 0.001) and K (p = 0.003) were identified as significant factors for differentiating among the three groups. Binary logistic analyses identified ADC (p = 0.001), K (p = 0.014), and K (p = 0.029) as independent predictors for the active status. The combination of ADC, K, and K performed better than MaRIA score (p = 0.028), for differentiating inactive and active status. MaRIA score was positively correlated with ADC (p < 0.001), K (p < 0.001), K (p < 0.001), and V (p = 0.001), however, negatively correlated with Fraction of ADC (p < 0.001).

Conclusion: The combination of MUSE-IVIM and DCE-MRI has been demonstrated to accurately stage inflammatory activity in CD.