Evolution of 3-D power Doppler indices of fetal brain in normal pregnancy.

We assessed the vascular indices of the anterior territory of the middle cerebral artery (MCA) in normal pregnancies using 3-D power Doppler (3DPD). A cross-sectional study was carried out on 90 normal pregnancies between 24 and 35 weeks. All examinations were performed by a single operator using a volumetric transducer. The anterior territory of the MCA was scanned and the volumes were captured using 3DPD. The sphere mode of the VOCAL program was used to calculate the following vascular indices: vascularization index (VI), flow index (FI) and vascularization and flow index (VFI). Models of polynomial regression and Pearson's correlation coefficient were used to evaluate the correlation between gestational age (GA) and the vascular indices. The 3DPD vascular indices had a low correlation with gestational age (VI - r = 0.324, p = 0.002; FI - r = 0.375, p < 0.001; VFI - r = 0.374, p < 0.001). There was a low correlation between GA and the 3DPD vascular indices of the anterior territory of the MCA.