Diffusion kurtosis MRI versus conventional diffusion-weighted imaging for evaluating inflammatory activity in Crohn's...

Area of Science:

• Radiology
• Gastroenterology
• Medical Imaging

Background:

• Crohn's disease (CD) is a chronic inflammatory bowel disease requiring accurate assessment of disease activity.
• Conventional diffusion-weighted imaging (DWI) has limitations in precisely quantifying intestinal inflammation.
• Diffusion kurtosis imaging (DKI) offers advanced diffusion metrics beyond standard apparent diffusion coefficient (ADC) measurements.

Purpose of the Study:

• To evaluate the effectiveness of DKI in grading the inflammatory activity of Crohn's disease.
• To compare DKI-derived parameters with conventional DWI metrics for inflammatory assessment in CD.
• To determine the diagnostic performance of DKI parameters in differentiating disease severity.

Main Methods:

• 38 patients with CD underwent 3T magnetic resonance enterography (MRE) with DKI (b values 0-2000 s/mm²).
• Bowel segments were graded for inflammation using the magnetic resonance index of activity (MaRIA) scale.
• DKI parameters (apparent diffusion for non-Gaussian distribution [D_app], apparent kurtosis coefficient [K_app]) and DWI (ADC) were compared with MaRIA scores.

Main Results:

• Significant differences in K_app, D_app, and ADC were observed across inactive, mild, and moderate-severe CD groups (P < 0.05).
• K_app, D_app, and ADC showed strong correlations with MaRIA scores (r = 0.862, -0.755, -0.713, respectively).
• K_app demonstrated superior correlation with MaRIA in moderate-severe CD (r = 0.647) compared to D_app and ADC. ROC analysis indicated high accuracy for K_app, D_app, and ADC in differentiating disease activity.

Conclusions:

• DKI is clinically feasible for assessing Crohn's disease.
• DKI parameters, particularly K_app, show strong potential for accurately grading CD inflammatory activity.
• DKI may offer advantages over conventional DWI for quantitative assessment of CD inflammation.