Fig. 2
A: Measurement of placental volume (PV, cm3) using 3D ultrasound volumes and VOCAL measuring technique by subtracting 1. total pregnancy volume and 2. gestational sac volume. B: utero-placental vascular volume obtained by semi-automated measurements using three-dimensional power Doppler ultrasound images and Virtual Reality (VR) visualization. 1. Slice view of a complete 3D power Doppler vascular volume at 9 weeks GA, with surrounding grey values representing the uterine tissue. 2. Volume view of Fig. B1 showing the total obtained pregnancy volume, after setting a threshold for grey values. 3. Volume view of the complete 3D Power Doppler vascular volume. The anatomic orientation of the vasculature in color is demonstrated in the lower insert, delineated by a dashed white line. 4. Volume view of the utero-placental vascular volume (uPVV, cm3), calculated by subtracting uterine and fetal vascular volumes using a virtual brush to erase vascular voxels up to the myometrial-placental border, leaving the utero-placental vascular volume, delineated by the dashed with line