High-field diffusion tensor imaging characterization of cerebral white matter injury in lipopolysaccharide-exposed fetal sheep.
BACKGROUND
In gyrencephalic species such as sheep, precise anatomical and microstructural characterization of the consequences of fetal inflammation remains scarce. The goal of this study was to characterize changes in white matter (WM) structure using advanced magnetic resonance imaging (MRI) following lipopolysaccharide (LPS) exposure in the preterm-equivalent fetal sheep.


METHODS
Preterm (0.7 gestation) fetal sheep received vehicle (Sham group) or LPS (LPS group), and fetal brains were collected 10 d later for subsequent ex vivo MRI. T1-weighted (T(1)W), T2-weighted (T(2)W), and diffusion tensor imaging (DTI) data were collected.


RESULTS
Fetuses exposed to LPS exhibited reductions in WM volume and corpus callosum thickness at 10 d recovery. Characteristic patterns of diffuse and focal WM lesions (necrosis or cysts) could be identified by various T1, T2, and DTI signal changes.


CONCLUSIONS
Fetal LPS exposure induces a pattern of injury characterized by diffuse and focal WM injury that closely reproduces that observed clinically in preterm infants. This work provides anatomical and microstructural MRI assessment, as well as histopathological correlates, of the consequences of LPS exposure in an animal model with a WM structure similar to that of the human brain. This work will help to further our understanding of MRI changes in preterm infants.
Department of Pediatrics, University of Geneva, Geneva, Switzerland. yohan.vandelooij@epfl.ch
Yohan
Y
van de Looij
Gregory A
GA
Lodygensky
Justin
J
Dean
François
F
Lazeyras
Henrik
H
Hagberg
Ingemar
I
Kjellmer
Carina
C
Mallard
Petra S
PS
Hüppi
Stéphane V
SV
Sizonenko
D000818:Animals; D001921:Brain / Q000033:anatomy & histology* / Q000187:drug effects; D008070:Lipopolysaccharides / Q000633:toxicity*; D008279:Magnetic Resonance Imaging; D012756:Sheep / Q000196:embryology*
D008070:Lipopolysaccharides