Quantitative evaluation of renal arteries using three-dimensional power Doppler ultrasonography and serum cystatin C for diagnosing fetal hydronephrosis

This study evaluated the predictive value of quantitative analysis of renal arteries using three-dimensional power Doppler ultrasonography (3D-PDU) and serum cystatin C (CysC) in diagnosing fetal hydronephrosis (HN). A total of 208 fetuses with HN (a case group) and 210 healthy fetuses (a control group) were selected for this study. 3D-PDU was used to measure vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of renal arteries in newborns. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate serum CysC level in umbilical cord blood. A receiver operating characteristic (ROC) curve was applied to evaluate the diagnostic power of renal artery index and serum CysC for fetal HN. Logistic regression analysis was performed to identify risk factors for fetal HN. Compared with the control group, VI and VFI obviously decreased and serum CysC level significantly increased in the case group. The VI and VFI were positively correlated with gestational age, but negatively correlated with the disease degree of fetal HN. However, serum CysC level was positively associated with the disease degree of fetal HN. VI and VFI were negatively correlated with the disease degree of fetal HN. ROC curves indicated that the 3D-PDU showed a highest value in diagnosing fetal HN, when the optimal cut-off value of VI = 6.275 (sensitivity = 84.3, specificity = 69.7) and serum CysC = 1.745 (sensitivity = 92.8, specificity = 76.2). Logistic regression analysis indicated that fetal HN was associated with VI, VFI, and serum CysC level. These findings elucidated that fetal renal VI, VFI and serum CysC could be useful diagnostic tools for fetal HN.