EP05.19: Assessment of fetal brain vascularisation in fetal growth restriction using 3D power angiography

To assess perfusion of different cerebral regions in normal fetuses and in those affected by fetal growth restriction (FGR) using 3D power Doppler angiography (3DPDA). 3DPDA were performed on 230 FGR pregnancies and 400 appropriate-for-gestational age (AGA) fetuses between 24-36 weeks of gestation. 3 FGR groups considered: 1 late-onset FGR (GA>34 weeks) with normal 2D Doppler flow measurements; 2 early-onset FGR (GA<34 weeks) with abnormal umbilical artery (UA) pulsatility index (PI), normal middle cerebral artery (MCA) PI; 3 early-onset FGR with abnormal 2D flow measurements in UA and MCA. We performed anterior cerebral artery (ACA) 2D Velocimetry for all the fetuses studied. 2 region of interest (ROI) of fetal brain studied: Power Doppler signals from the fetal brain were recorded in the plane of section that traverses the third ventricle and thalami in the central portion of the brain. The cavum septi pellucidi must be visible in the anterior portion of the brain. The first ROI (“Frontal Zone”), sprinkled by ACA, was obtained tracing a contour passing through the anterior side of CSP surrounding part of the temporal and frontal bones. The second ROI (“Temporal Zone”), sprinkled by MCA, was that zone of the brain defined by a rectangle obtained tracing a contour from temporal bones including the width of CSP. In fetuses “early onset FGR” with pathological UA velocimetry, normal ACA values and with/without abnormal MCA findings, VFI values demonstrated increased blood flow in the temporal zone. In fetuses “late onset FGR” with normal 2D MCA velocimetry VI and VFI values demonstrated increased blood flow in the frontal zone and decreased blood flow in the temporal one. 96% of fetuses “late onset FGR” revealed vasodilatation of ACA using 2D velocimetry. 3DPDA recognised the “Frontal Brain Sparing” in “late onset IUGR” without any pathological 2D Doppler MCA velocimetry demonstrating a vascular redistribution with preferential increment in bloody supply to the frontal region.