Reproducibility of three-dimensional power Doppler placental vascular indices in pregnancies between 26 and 35 weeks

Abstract

Assess intra and interobserver reproducibility of three-dimensional power Doppler (3DPD) placental vascular indices in normal pregnancies between 26 and 35 weeks. Thirty 3D volumes were captured by one observer and stored for analysis. Vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated from the spherical placental tissue samples obtained through the automatic Virtual Organ Computer-aided AnaLysis (VOCAL). Two observers analyzed the stored volumes and calculated the indices and their findings were compared. Intraclass correlation coefficients (ICCs) were used to analyze intra and interobserver correlations. Data were analyzed using confidence intervals, reliability coefficients and Bland-Altman graphs with concordance limits. All three indices had good intra and interobserver reproducibility. Intraobserver ICCs for the three indices were > 0.90. The FI had the highest ICC (0.99), the highest interobserver ICC (0.98) and the best concordance on the Bland-Altman graphs. 3DPD placental vascular indices obtained using the automatic sphere mode had a good intra and interobserver reproducibility for pregnancies between 26 and 35 weeks. The FI obtained the highest reproducibility scores.