title: Impact of therapeutic hypothermia on MRI diffusion changes in neonatal encephalopathy.
abstract: OBJECTIVE
  The objective of this work was to determine the impact of therapeutic hypothermia (TH) on the magnitude and time course of mean diffusivity (MD) changes following hypoxic-ischemic encephalopathy (HIE) in newborns.
  
  
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  TH slows the evolution of diffusion abnormalities on MRI following HIE in term infants.
authors.affiliation: Neonatology Unit, Alix de Champagne, Reims, France.
authors.forename: N
authors.initials: N
authors.lastname: Bednarek
authors.forename: A
authors.initials: A
authors.lastname: Mathur
authors.forename: T
authors.initials: T
authors.lastname: Inder
authors.forename: J
authors.initials: J
authors.lastname: Wilkinson
authors.forename: J
authors.initials: J
authors.lastname: Neil
authors.forename: J
authors.initials: J
authors.lastname: Shimony
mesh_terms: D001238:Asphyxia Neonatorum / Q000175:diagnosis / Q000628:therapy*; D001921:Brain / Q000473:pathology; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000628:therapy*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005311:Fetal Hypoxia / Q000175:diagnosis / Q000628:therapy*; D005500:Follow-Up Studies; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis / Q000628:therapy*; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D009460:Neurologic Examination; D011379:Prognosis; D012189:Retrospective Studies; D051598:Whole Body Imaging