Value of magnetic resonance imaging texture analysis in evaluating renal allograft injury

Objective: To explore the value of magnetic resonance imaging (MRI) texture analysis in evaluating renal allograft injury. Methods: A retrospective review was performed on sixty-six patients who underwent allograft renal transplantation (42 males, 24 females; age range, 22-63 years; mean age, (40±10) years) between November 2013 and December 2016. All the patients were divided into three groups according to their eGFR on the day of MRI examination: normal renal allograft function (nRAF) group (n=15), mild to moderate renal allograft injury (mRAI) group (n=18), and severe renal allograft injury (sRAI) group (n=33). All the patients underwent conventional T(2) weighted image (T(2)WI), susceptibility weighted imaging (SWI), and blood-oxygen level dependent (BOLD) MRI examination. MRI texture features of renal allograft were extracted. The texture features based on T(2)WI, SWI, and BOLD with absolute correlation coefficient of eGFR greater than or equal to 0.3 (P<0.05)and also with the highest Z value for Boruta algorithmwere selected. The diagnostic performance of the selected texture features in differentiating the three groups was assessed by receiver operating characteristic (ROC) curve analysis. Results: T(2)WI_Perc.50%, SWI_Perc.01%, BOLD_S(4,4)Contrast, and BOLD_S(5,5)Correlat with absolute correlation coefficient of eGFR greater than or equal to 0.3 (P<0.05) and also with the highest Z value for Boruta algorithm were selected. The AUC for T(2)WI_Perc.50%, SWI_Perc.01%, and BOLD_S(5,5)Correlat in differentiating the nRAF group with the mRAI group was 0.785, 0.720, and 0.700. The AUC for T(2)WI_Perc.50%, SWI_Perc.01%, BOLD_S(4,4)Contrast, and BOLD_S(5,5)Correlat in differentiating the nRAF group with the sRAI group was 0.687, 0.733, 0.784, and 0.737.The AUC for BOLD_S(4,4) Contrast in differentiating the mRAI group with the sRAI group was 0.667. Conclusion: MRI texture analysis can provide valuable information for evaluating renal allograft injury.