3D Power Doppler May Be Useful as a Complementary Technique to Grayscale in the Prenatal Diagnosis of Placenta Accreta

Objective: To assess the value of adding three-dimensional (3D) power Doppler (as a diagnostic technique) to grayscale in the prenatal diagnosis of placenta accreta. Material and Methods: One hundred pregnant women with persistent placenta previatotalis (after 28 weeks' gestation) were prospectively enrolled into this study. Gray-scale transabdominal ultrasound was performed to detect loss of the subendometrial echolucent zone and other abnormalities suggestive of placenta accreta. Then a targeted examination of angioarchitecture in the basal and lateral views of the placenta was carried out using 3D power Doppler. The ultrasound findings were analyzed with reference to the final diagnosis made during Cesarean delivery. Results: Placenta accreta and its variants (including increta and percreta) were confirmed in 31 patients at the time of Cesarean delivery, 'numerous coherent vessels' visualized using 3D power Dopplerin the basal view was the best single criterion for the diagnosis of placenta accreta, with a sensitivity of 96.8% and a specificity†of 91.3%. If we depend on one criterion to be of diagnostic value when using each ultrasound technique, then 3D power Doppler would have the best positive predictive value (75.6%), followed by gray-scale (60.4%). The majority of patients with placenta accreta showed multiple characteristic features on ultrasound imaging. In contrast, those patients with a false-positive diagnosis (i.e. the final diagnosis was placenta previa alone) tended to show isolated ultrasound markers. Conclusion: 3D power Doppler may be useful as a complementary technique for the prenatal diagnosis or exclusion of placenta accreta.