Serial Quantitative Diffusion Tensor MRI of the Term Neonates with Hypoxic-Ischemic Encephalopathy (HIE)

Abstract

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. 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. 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. 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.