Assessment of Cerebral Microvascular Development in Preterm Neonates Using Ultrafast Power Doppler Imaging

The incidence of preterm birth is reported as more than 10% in 2020 all over the world, and the disability and mortality rate are high due to incomplete development. The microvascular developments of neonates with different gestational ages (GAs) are unknown, which are related to cerebral development. This study assessed the cerebral microvascular development of preterm neonates with different GAs using the ultrafast power Doppler imaging technique.

Seventy neonates were enrolled, including 7 full-term (GA = 37 weeks) and 63 preterm neonates (ranging from extremely preterm [GA ≤ 28 weeks] to late preterm [GA = 36 weeks]). Quantitative metrics including microvascular area (MArea) and microvascular diameter (MDiam) were evaluated in three regions of interest (ROIs): the cingulate gyrus (ROI 1), the frontal and parietal junction (ROI 2), and a branch of the anterior cerebral artery near the central sulci (ROI 3). Electroencephalogram signals were recorded and amplitude-integrated electroencephalography (aEEG) was used to measure the brain activity. Statistical correlations were assessed among microvascular quantitative metrics, GA, and aEEG.

All the microvascular quantitative metrics have a statistically significant (p < 0.05) positive correlation with GA and aEEG. MArea in ROI 1 has the highest correlation coefficient of 0.67 (p < 0.0001) with GA. Similarly, MArea in ROI 1 has the highest correlation coefficient of 0.53 (p < 0.0001) with aEEG.

This study showed that MArea- and MDiam-related parameters were associated with increasing GA in preterm neonates, suggesting a trend toward cerebral microvascular maturation.