title: Morphological and hemodynamic magnetic resonance assessment of early neonatal brain injury in a piglet model.
abstract: OBJECTIVE
  To investigate the utility of functional and morphological magnetic resonance imaging (MRI) to assess the extent of brain injury in a hypoxia-ischemia (HI) piglet model and further to validate that the desired ischemic injury was successfully induced.
  
  
  METHODS
  MRI was performed at 1.5 T in anesthetized piglets (N = 10, age = 12-36 hours). Relative cerebral blood flow (rCBF), time-to-peak (TTP) contrast, and apparent diffusion coefficient (ADC) were estimated at different time points pre-, during, and post-HI. The effect following bilateral clamping of the carotid arteries was assessed by contrast-enhanced MR angiography (MRA) and phase contrast MR angiography (PCA) (N = 4).
  
  
  RESULTS
  A linear correlation was observed between relative cerebral perfusion reduction and cerebral ADC during HI (r(2) = 0.85, P < 0.05). There was no correlation between rCBF reduction during 30 minutes of HI and cerebral ADC after 30 or 150 minutes of reperfusion/reoxygenation (RR).
  
  
  CONCLUSIONS
  The combination of morphological and functional (perfusion and diffusion) MRI enabled consistent assessment of both the presence and absence of complete occlusion as well as the functional significance of the occlusion.
authors.affiliation: Department of Pediatric Research, Rikshospitalet University Hospital, Oslo, Norway. b.h.munkeby@klinmed.uio.no
authors.forename: Berit H
authors.initials: BH
authors.lastname: Munkeby
authors.forename: Kristin
authors.initials: K
authors.lastname: Lyng
authors.forename: Jahn Frederik
authors.initials: JF
authors.lastname: Frøen
authors.forename: Eldrid H
authors.initials: EH
authors.lastname: Winther-Larssen
authors.forename: Jan Henrik
authors.initials: JH
authors.lastname: Rosland
authors.forename: Hans-Jørgen
authors.initials: HJ
authors.lastname: Smith
authors.forename: Ola Didrik
authors.initials: OD
authors.lastname: Saugstad
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D038524:Diffusion Magnetic Resonance Imaging; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis* / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D013552:Swine