Hypoxic ischaemic encephalopathy: correlation between ultrasound and computed tomography

Area of Science:

• Neonatal neurology
• Pediatric neuroimaging
• Perinatal medicine

Background:

• Hypoxic ischaemic encephalopathy (HIE) is a significant cause of neurodevelopmental deficits in infants.
• Distinguishing between haemorrhagic and non-haemorrhagic HIE is crucial for appropriate management.
• Cerebral sonography is established for detecting haemorrhagic HIE, but its utility for non-haemorrhagic forms requires further investigation.

Observation:

• This study presents three cases of non-haemorrhagic HIE in infants with varying gestational ages and clinical presentations.
• The cases include periventricular leukomalacia in a premature infant, multicystic encephalopathy in a term newborn, and circumscript ischaemic leukomalacia in an older infant.
• Correlation between serial cerebral sonography and computed tomography (CT) was performed.

Findings:

• Non-haemorrhagic HIE demonstrates high echogenicity on ultrasound in the initial week post-insult, corresponding to hypodensities on CT.
• Cerebral sonography is effective in identifying non-haemorrhagic HIE, presenting as global or circumscript areas of increased echogenicity.
• In cases of periventricular leukomalacia, CT scans provide no additional diagnostic information beyond ultrasound.

Implications:

• Cerebral sonography is a valuable, non-invasive tool for diagnosing non-haemorrhagic HIE, particularly in premature infants.
• CT scans may be avoidable for diagnosing periventricular leukomalacia, reducing radiation exposure and healthcare costs.
• For term newborns and older infants with HIE, CT remains essential for comprehensive assessment of brain injury extent.