Sonographic and MRI findings in neonates following selective cerebral hypothermia

Hypoxic ischemic insults during labor remain an important cause of brain injury in term and near-term neonates. Selective cerebral hypothermia is a potentially neuroprotective rescue therapy. Ultrasonography (US) and magnetic resonance imaging (MRI) are routinely used to visualize intracranial changes in neonatal hypoxic-ischemic injuries.

We attempted to describe all pathological findings on US and MRI in the brains of our patients following selective cerebral hypothermia.

Twenty-nine neonates with hypoxic-ischemic encephalopathy (HIE) following therapeutic cooling were assessed with cranial ultrasound (US) and magnetic resonance imaging (MRI). The findings were compared with the clinical outcome.

Over one-fourth (27.6%) of the examined infants had a normal brain on MRI (with only 17.2% on US). Involvement of the basal ganglia and thalami was one of the most frequent findings in our material (9/29 = 31% on MRI, and 7/29-24.1% on US). Cerebral parenchymal hemorrhage was detected on MRI in as many as 7 (24.1%) and cerebellar parenchymal hemorrhage in 4 (13.8%) infants. The loss in the gray-white matter differentiation ('fuzzy brain'), usually transient on US, was observed in 79.3% of the neonates. Diffusion restriction in the callosal splenium (13.8%) and hyperechoic thalami and basal ganglia were strictly correlated to a significantly higher incidence of severe developmental delay.

Abnormalities on MRI and US were observed in 75% of newborns with hypoxic-ischemic encephalopathy treated with therapeutic hypothermia.