Impact of therapeutic hypothermia on MRI diffusion changes in neonatal encephalopathy
Bednarek N et al. – Therapeutic hypothermia (TH) slows the evolution of diffusion abnormalities on MRI following hypoxic–ischemic encephalopathy (HIE) in term infants.Methods
- Cerebral MRI scans of infants undergoing whole body TH for HIE from 2007 to 2010 were retrospectively reviewed.
- The data were analyzed identically to a control group of newborns with HIE previously published, prior to the development of TH.
- Anatomic injury was defined on T1– and T2–weighted (“late”) MRI obtained after the fifth day of life.
- Since MD values vary regionally, the ratios of MD values for injured and normal tissue were calculated for areas of injury.
- Normal values were obtained from corresponding brain regions of 12 infants undergoing TH who had no injury on MRI studies.
- Twenty–three of 59 infants who underwent TH and MRI displayed cerebral injury on late MRI and were included in the study.
- MD ratios were decreased in all injured infants within the first 7 days of life.
- The return of MD to normal (pseudonormalization) occurred after the tenth day as compared to 6–8 days in the control group.
- Infants with severest injury demonstrated greater reduction in MD, but no difference in time to pseudonormalization.