論文ID: 2022-1763
Neonatal hypoxic-ischemic encephalopathy (HIE) causes significant and life-long neurologic disability. Therapeutic hypothermia has become the standard treatment for neonates with moderate or severe HIE. It improves overall neurologic outcomes and reduces the incidence of death and disability. Magnetic Resonance Imaging (MRI) assists in defining the nature and extent of HIE. This review discusses the recent topics on the application of MRI on HIE. The following issues on the MRI findings are discussed;
1. The correlation of negative pseudonormalization of diffusion-weighted imaging (DWI) (residual high signal lesions on DWI beyond the first week) and clinical outcome.
2. MRI findings of “total brain injury”, as a new category of HIE caused by prolonged profound asphyxia, are shown with the serial MRI findings, including those from the first and second weeks of life.
3. Pontine and cerebellar injury: to characterize the MRI features of pontine and cerebellar injuries and a background HIE pattern and to localize the injury sites.
4. Pre-Wallerian degeneration preceding Wallerian degeneration (WD): The DWI obtained immediately after a brain injury demonstrates acute corticospinal injury preceding WD, known as “pre-Wallerian degeneration”. It has been observed in infants with neonatal arterial stroke, and neonates with HIE. The characteristics of MRI findings of pre-WD are shown with the background HIE pattern.
5. Diffusion restriction in optic radiation is commonly observed among HIE neonates. This diffusion restriction was associated with transsynaptic neuronal degeneration.
6. Injury to the mammillary body in term neonates with HIE has emerged as a topic in neonatal imaging. Mammillary body injuries during the neonatal period cause mammillary body atrophy and are associated with memory disturbance during later childhood at around 10 years of age.
