Statistical Analysis

All statistical analyses were performed with statistical software (ver. 16.0; SPSS Inc., Chicago, IL, USA). Kolmogorov-Smirnov tests were performed to evaluate for normality. ADC, F_P, and eGFR values were found to be normally distributed. Two-tailed paired Student t tests were used to compare DWI parameters in the cortex and medulla. The differences of ADC_T, ADC_D, and F_P values among 4 groups were performed with an one-way analysis of variance (ANOVA) with Student-Newman-Keuls post hoc contrasts, to detect significant differences between subgroups. Renal cortical ADC_T and ADC_D were applied with the Kruskal-Walls test to detect heterogeneity of variance, and further multiple intergroup paired comparisons were performed with the Nemenyi test. The Pearson correlation analysis was performed to determine relationships between the diffusion parameters and eGFR. The researchers applied diffusion parameters to perform a receiver operating characteristic (ROC) curve analysis to predict normal and mildly decreased renal function (eGFR ≥ 60 mL/min/1.73 m²) in renal transplanted recipients. The ROC curve was used to evaluate the diagnostic performances of diffusion parameters in predicting normal and mildly decreased renal function. A p value of less than 0.05 was assumed to represent a significant difference.