Fig. 3From: Three-dimensional power Doppler ultrasound evaluation of placental blood flow in normal monochorionic diamniotic twin pregnanciesScatterplots of vascularization index, flow index and vascularizationflow index versus gestational age. Curve regression lines indicate the mean values. VI = exp. (4.369–28.533/GA) (R2 = 0.699, p < 0.05); FI = exp. (3.916–13.003/GA) (R2 = 0.511, p < 0.05); VFI = exp. (3.577–37.468/GA) (R2 = 0.675, p < 0.05). GA, Gestational age; FI, Flow index; VFI, Vascularizationflow index; VI, Vascularization indexBack to article page