Serial quantitative diffusion tensor MRI of the term neonates with hypoxic-ischemic encephalopathy (HIE)

Aim: To determine the altered pattern of fractional anisotropy (FA) and mean diffusivity (MD) change in brain parenchyma in serially studied neonates with mild or moderate hypoxic ischemic injury (HIE) within 7 days after birth and again at the age of three months. Methods: Serial diffusion tensor imaging (DTI) was performed at two-time points in term neonates with mild (n = 7) and moderate (n = 10) HIE and age/sex-matched controls (n = 7). Neurodevelopmental outcome was assessed at the time of the 2nd study. Results: On comparing FA and MD changes over time using two-way analysis of variance between neonates with HIE and controls, we observed significant differences in age-related FA increase (p < 0.05) in anterior limb of internal capsule and periventricular white matter of parietal, occipital, and temporal lobes. Significant differences in age-related MD decrease (p < 0.05) was observed in the caudate nuclei, and temporal white matter among these groups. Significant positive correlation was observed between neurodevelopmental outcome and FA. Conclusion: The results suggest that abnormal FA and MD values help in early and more accurate assessment of microstructural damage in HIE that may have predictive value for long-term neurofunctional outcome in these neonates.