Morphological and hemodynamic magnetic resonance assessment of early neonatal brain injury in a piglet model.
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.
Munkeby
Berit H
BH
Department of Pediatric Research, Rikshospitalet University Hospital, Oslo, Norway. b.h.munkeby@klinmed.uio.no
Lyng
Kristin
K
Frøen
Jahn Frederik
JF
Winther-Larssen
Eldrid H
EH
Rosland
Jan Henrik
JH
Smith
Hans-Jørgen
HJ
Saugstad
Ola Didrik
OD
Bjørnerud
Atle
A
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