Cerebral superb microvascular imaging in preterm neonates: in vivo evaluation of thalamic, striatal, and extrastriatal angioarchitecture

Purpose: To explore the potential of superb microvascular imaging (SMI) in visualizing brain microvessels in preterm neonates of different gestational ages (GA). Methods: In this retrospective, observational pilot study, 15 preterm newborns were equally divided into GA groups: extremely (GA < 28 weeks), very (28–31 weeks), and moderate to late (32–37 weeks) preterm. All patients underwent conventional transcranial ultrasounds during the first day of life following the American Institute of Ultrasound in Medicine practice guidelines. SMI was then performed; based on their SMI morphology and location, brain microvessels were classified as extrastriatal (cortical and medullary), striatal, or thalamic. Two examiners independently classified vessels as visible or invisible. To assess the association between vessel visibility and GA, binomial logistic regression analysis (separate for each microvessel group) was performed, taking visibility as a dependent variable and both examiners and GA as predictor variables. Results: A statistically significant difference among GA groups was found in sex (P = 0.030), birth weight (P = 0.007), and Apgar score within 1 min after birth (P = 0.024). Microvascular visibility increased with GA for superficial vessels (P < 0.05 for both cortical and medullary), while striatal and thalamic vessels were visible in all neonates irrespective of their GA. Conclusions: SMI technology shows promise to assess brain microvasculature in preterm neonates, even potentially providing data on early brain development.