Association between liver diffusion-weighted imaging apparent diffusion coefficient values and other measures of liver disease in pediatric autoimmune liver disease patients

Background Multiple quantitative magnetic resonance imaging (MRI) methods have been described to noninvasively detect and characterize liver fibrosis, including diffusion-weighted imaging (DWI). Purpose To evaluate associations between liver MRI DWI apparent diffusion coefficient (ADC) values and clinical factors and other quantitative liver MRI metrics in pediatric patients with autoimmune liver disease (AILD). Materials and methods Fifty-seven research liver MRI examinations performed from January 2017 to August 2018 for pediatric AILD registry participants were evaluated. Liver DWI ADC values, liver and spleen stiffness (kPa), and iron-corrected T1 (cT1; Perspectum Diagnostics) were measured at four anatomic levels. Participant age, sex, and laboratory data (alanine aminotransferase [ALT], total bilirubin, alkaline phosphatase, gamma-glutamyl transferase [GGT]) were recorded. Spearman’s rank-order correlation (rho) and multiple linear regression were used to evaluate the associations between liver ADC values and predictor variables. Results Mean (SD) participant age was 14.8 (4.0) years, 45.6% (26/57) were girls. Mean liver DWI ADC value was 1.34 (0.14 × 10 −3 ) mm 2 /s. Liver ADC values showed weak to moderate correlations with liver stiffness ( r = − 0.42, p = 0.001), spleen stiffness ( r = − 0.34; p = 0.015), whole-liver mean cT1 ( r = − 0.39; p = 0.007), ALT ( r = − 0.50; p = 0.0001), and GGT ( r = − 0.48; p = 0.0004). Multiple linear regression showed liver stiffness ( p = 0.0009) and sex ( p = 0.023) to be independent predictors of liver ADC values. Conclusion Liver DWI ADC values are significantly associated with liver and spleen stiffnesses, liver cT1, ALT, GGT, and participant sex, with liver stiffness and sex remaining significant at multivariable regression. Liver ADC ultimately may play a role in multi-parametric prediction of chronic liver disease/fibrosis severity.