Quantitative liver MRI assessment in hemodialysis ptients

ZHANG Yu; WANG Xinyu; LYU Haijuan; LIU Hu; ZHAO Hongwei

doi:10.20258/j.cnki.1006-9011.2025.04.018

Abstract：Objective This study aims to evaluate the impact of the size of regions of interest(ROIs)on R2* values and proton density fat fraction(PDFF)measurements during quantitative liver MRI analysis in patients undergoing hemodialysis.Methods Fifty patients undergoing hemodialysis were selected for upper abdominal MRI scans to obtain PDFF and R2* values for liver segments S2/3,S4,S5/6,S7,and S8.Two radiologists independently measured two different sizes of ROIs:large ROIs of 400～500 mm2 and small ROIs of 80～100 mm2.Additionally,we measured PDFF and R2 values by delineating the maximum transverse section of the liver.The intraclass correlation coefficient(ICC)was used to evaluate the consistency of PDFF and R2*measurements between the two radiologists for both large and small ROIs.The Kruskal-Wallis test was employed to analyze the differences in PDFF and R2* values among the different ROIs sizes.Results The PDFF measurements by the two radiologists across different liver segments showed high consistency(ICC:0.845～0.945),with better consistency for large ROIs compared to small ROIs.The R2* values in both large and small ROIs across different liver segments exhibited extremely high consistency(ICC:0.988～0.998).Each radiologist demonstrated high consistency in their measurements of PDFF and R2* for both large and small ROIs(PDFF ICC:0.771～0.978,R2* ICC:0.989～0.999),indicating that each radiologist's measurements for large and small ROIs were highly consistent.Analyzing the average values measured by the two radiologists,the differences in PDFF val-ues among large,small,and maximum plane ROIs were statistically significant(Kruskal-Wallis test statistic=15.83,P<0.001),while the differences in R2* values among the three ROIs were not significant(Kruskal-Wallis test statistic=0.012,P=0.994).The overall hepatic mean PDFF for large ROIs was(2.18±1.91)％,and the R2* value was(119.23±135.30)s⁻1.Conclusion In the quantitative liver MRI evaluation of hemodialysis patients,selecting the appropriate ROIs size is crucial.For PDFF measurements,larger ROIs are recommended,while R2* values are not affected by the size of the ROIs.