OC162: Assessment of brain vascularization and blood flow in human fetus using quantitative three‐dimensional power Doppler sonography

Abstract

Objectives: New three-dimensional (3D) ultrasound technologies allow the assessment of the overall vascularization within a given volume of tissue. We applied 3D ultrasound to the study of fetal brain with two aims: to evaluate the brain perfusion in normal fetuses, and to detect the presence of eventual vascular dominance in fetal brain by comparing left to right hemisphere vascularization. Methods: We studied 65 normal fetuses of gestational age ranging from 21 to 40 weeks using 3D real-time ultrasound equipment that supports volume contrast imaging technology (Voluson 730 Expert, General Electric). The vascularization index (VI), the flow index (FI) and the vascularization–flow index (VFI) are calculated by a built-in software. These indices were derived from spherical volumes acquired in specifical anatomical regions, obtained from a transverse section of the fetal head at the level of the thalami and cavum septi pellucidi. We calculated the regression of VI, FI and VFI values of the overall vascularization, and the median VI, FI and VFI values of the right and left hemispheres. Results: VI, FI and VFI values of overall brain perfusion showed a slight, but not significant increase from 21 to 40 weeks of gestational age. Median VI (left vs. right, 2.20 (range, 0.02–14.32) vs. 1.04 (range, 0.01–12.71), P = 0.014), median FI (left vs. right, 21.68 (range, 18.18–41.36) vs. 18.25 (range, 16.43–39.40), P = 0.030) and median VFI (left vs. right, 0.66 (range, 0.06–5.38) vs. 0.33 (range, 0.04–4.32), P = 0.023) obtained by sampling the left hemispheres were significantly higher than the values obtained by sampling the right hemispheres. Conclusions: We suggest that quantitative three-dimensional power Doppler sonography can be used to study the in-utero development of the fetal brain vascular network. Moreover, we could demonstrate the presence of a vascular dominance of the left hemisphere in the fetal brain.