3-D ultrasound in the study of placental vascularization. Application of vocal technique. A case-control study and a review of literature

Background. The study of resistances of the uterine and umbilical arteries represents the principal method for the prediction and diagnosis of adverse pregnancy outcomes such as preeclampsia (PE) and intra-uterine growth restriction (IUGR). Three-Dimensional (3D) power Doppler allows a quantification of vascularization by calculating the Vascularization index, Flow Index and Vascularization Flow Index (VI, FI and VFI). Objective. The aim of this study is to investigate 3D power Doppler ultrasound indices as VI, FI and VFI in the assessment of placental perfusion in the assessment of placental perfusion in pregnancies with late onset of IUGR cases and Doppler abnormalities in comparison with a control group of uncomplicated pregnancies. Study design. A prospective, single-institution analysis of 12 pregnant patients presenting with IUGR and Doppler velocimetry alterations (cases) and 31 pregnant patients with normal fetal growth and Doppler values (controls) was carried out. All patients underwent a 2D and 3D ultrasound scan. 3D was carried out using the VOCAL software calculating VI, FI, VFI. Results. Mean VI and VFI indices, mean uterine arteries resistant index and PIUA/PIMCA ratio in the case group were statistically significant lower than in the control group VI (p =0.007), VFI (p = 0.034), PIUA/PIMCA ratio (p = 0.003). Average systolic, diastolic blood pressure, and mean arterial pressure were higher in the case group. Conclusion. 3D power Doppler applied to VOCAL and flow indices of the placental bed represents a new method to provide additional information about placental perfusion, both for physiological and IUGR complicated pregnancies. Studies on larger population and standardization of the technique are needed.