Temporal evolution of MR perfusion in neonatal hypoxic-ischemic encephalopathy

Area of Science:

• Neonatal neurology
• Neuroimaging
• Pediatric radiology

Background:

• Neonatal hypoxic-ischemic (HI) encephalopathy is a severe condition affecting newborns.
• Assessing brain injury and predicting outcomes in these infants is critical.

Purpose of the Study:

• To examine the changes in brain perfusion-weighted magnetic resonance imaging (PWI-MRI) over time in infants with severe HI encephalopathy.
• To explore the relationship between these PWI changes and subsequent neurodevelopmental outcomes.

Main Methods:

• Two neonates with HI encephalopathy underwent early and late MRI scans, including PWI.
• Perfusion maps were analyzed for relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV).
• Three normal neonates served as controls; patients were followed until eight months of age.

Main Results:

• Early PWI scans revealed whole-brain hyperperfusion (elevated rCBF and rCBV) in HI infants compared to controls.
• Late scans showed persistent hyperperfusion in cortical gray matter, with normalization in white matter and basal ganglia.
• Diffusion-weighted imaging normalized, while T2-weighted images showed extensive lesions; both patients had poor neurodevelopmental outcomes.

Conclusions:

• Perfusion-weighted MRI evolution in HI encephalopathy differs from diffusion-weighted imaging and remains abnormal for over a week.
• Persistent PWI abnormalities may indicate ongoing injury mechanisms in severe neonatal HI encephalopathy.
• Tracking PWI changes could offer a method for predicting neurodevelopmental outcomes.