Prospective evaluation of term neonate brain damage following preceding hypoxic sentinel events using enhanced T₂* weighted angiography (eSWAN)

Abstract

Purpose: To evaluate the brain damage of term neonates with evidence of a preceding hypoxic sentinel event using eSWAN prospectively. Methods: The study was approved by the institutional research ethics committee. Among the neonates who were examined during the first 8 days after birth with conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI) and eSWAN, 39 neonates with a preceding acute hypoxic sentinel event were divided into two groups: the hypoxic ischaemic encephalopathy (HIE) group and the high-risk group. Twenty-five neonates were normal control subjects. Conventional MRI, DWI, and T₂* and R₂* maps from eSWAN were assessed. T₂* and R₂* values from T₂* and R₂* maps were calculated in predefined regions in the HIE and high-risk groups and then compared with those in control subjects. Results: The neonates in the HIE and high-risk groups showed a high percentage of cerebral oedema and periventricular white-matter (PWM) lesions. Cerebral oedema and haemorrhagic lesions of PWM were more highly visible on the T₂* map compared with conventional MRI: cerebral oedema was illustrated as a high T₂* area and haemorrhagic lesions had a significantly lower T₂* on the T₂* map. Lower R₂* values of lentiform nuclei (LN) and a higher T₂* and lower R₂* of frontal white matter (FWM) were found in neonates in the HIE group relative to those of normal controls. The T₂* value of LN in the high-risk group was higher than that of the normal controls. Conclusions: The T₂* map from eSWAN is useful in detecting cerebral oedema and haemorrhagic lesions of PWM in neonates. The measurement of T₂* and R₂* values is helpful in assessing the LN and FWM damage in neonates following a hypoxic sentinel event.

KEYWORDS: :

• neonate
• hypoxic sentinel event
• T₂* value
• R₂* value

Acknowledgements

The authors would like to thank the support of all staff members at the Medical Imaging Centre, NICU, and postnatal wards. They would also like to thank Prof. Chen QS of the epidemiology teaching office who performed the statistical analysis in this report.