Shear wave elastography of placenta: in vivo quantitation of placental elasticity in preeclampsia

Abstract

PURPOSE We aimed to evaluate the utility of shear wave elastography (SWE) for assessing the placenta in preeclampsia disease. METHODSA total of 50 pregnant women in the second or third trimes-ter (23 preeclampsia patients and 27 healthy control sub-jects) were enrolled in the study. Obstetrical grayscale and Doppler ultrasonography, SWE findings of placenta, and pre-natal/postnatal clinical data were analyzed and the best SWE cutoff value which represents the diagnosis of preeclampsia was determined. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnos-tic accuracy of preeclampsia were calculated based on SWE measurements.RESULTSMean stiffness values were much higher in preeclamptic pla-centas in all regions and layers than in normal controls. The most significant difference was observed in the central pla-cental area facing the fetus where the umbilical cord inserts, with a median of 21 kPa (range, 3-71 kPa) for preeclampsia and 4 kPa (range, 1.5-14 kPa) for the control group (P < 0.01). The SWE data showed a moderate correlation with the uterine artery resistivity and pulsatility indices. The cutoff val-ue maximizing the accuracy of diagnosis was 7.35 kPa (area under curve, 0.895; 95% confidence interval, 0.791-0.998); sensitivity, specificity, PPV, NPV, and accuracy were 90%, 86%, 82%, 92%, and 88%, respectively.CONCLUSIONStiffness of the placenta is significantly higher in patients with preeclampsia. SWE appears to be an assistive diagnostic tech-nique for placenta evaluation in preeclampsia.