To describe the ultrasound presentation of the brain and cerebral hemodynamics in neonates with hypoxic-ischemic encephalopathy (HIE) by comparison with control subjects.

During June 2012 to April 2013, full term neonates who had clinical evidence of HIE were enrolled. Healthy newborns without HIE were used as a control group. Cerebral parenchyma, size of lateral ventricles and hemodynamic parameters of cerebral arteries were studied using two-dimensional duplex and color Doppler ultrasound. Neonates with moderate and severe HIE were followed-up with ultrasound for at least 3 months.

A total of 158 consecutive neonates (82 boys and 76 girls), including 54 with mild HIE, 60 with moderate HIE and 44 with severe HIE were included. One hundred and twenty healthy newborns were randomly selected as a control group. Abnormal ultrasound findings of brain parenchyma were found in 25/54 (46.3%) neonates with mild HIE whereas they were found in 58/60 (96.7%) neonates with moderate HIE and 44/44 (100%) neonates with severe HIE. Almost all neonates with severe HIE had decreased cerebral artery blood flow velocity and increased resistance index of cerebral arteries. Of the 104 neonates with moderate or severe HIE, follow-up ultrasound examination revealed cystic parenchymal lesions in 12/104 (11.5%), progressive ventricular dilatation and brain atrophy in 12/104 (11.5%), mild ventricular dilatation in 15/104 (14.4%) and leukoencephalomalacia in 2/104 (1.9%) neonates.

Ultrasound features such as the size of lateral ventricles, altered brain parenchymal echogenicity and cerebral blood flow parameters are useful for the early diagnosis of HIE and help predict outcome.