In vivo assessment of experimental neonatal excitotoxic brain lesion with USPIO-enhanced MR imaging.
OBJECTIVE
To assess the feasibility of magnetic resonance imaging (MRI) enhanced with ultrasmall superparamagnetic particles of iron oxide (USPIO) for assessing excitotoxic brain lesions in an experimental model of neonatal periventricular white matter (PWM) lesions.


METHODS
Brain lesions were induced by intracerebral injection of ibotenate in 14 newborn rats. Pre- and post-USPIO T2-weighted MRI was performed in seven of them (group A) and in five control newborns (group C). In seven newborns with induced cerebral lesions, USPIO-enhanced MRI was not performed (group B). We compared the signal intensity of the lesion to the contralateral unaffected brain (lesion-to-brain contrast, LBC) and the lesion signal-to-noise ratio (SNR) before and after USPIO injection. MR imaging was correlated with histology.


RESULTS
USPIO injection significantly (P<0.05) decreased LBC and SNR of brain lesion but induced no changes in normal controls. The densities of macrophages and iron-laden cells were higher on the lesion side than on the contralateral side (P<0.05). Neither lesion size nor the surrounding macrophage infiltrate was significantly different between groups A and B.


CONCLUSIONS
Post-USPIO T2-weighted MRI demonstrated negative enhancement of neonatal excitotoxic brain lesion. USPIO injection does not appear to exacerbate brain lesions.
Alison
Marianne
M
INSERM U676, Hopital Robert Debre, AP-HP, 48 Bd Serurier, 75019, Paris, France. marianne.alison@rdb.aphp.fr
Azoulay
Robin
R
Chalard
François
F
Gressens
Pierre
P
Sebag
Guy
G
D000818:Animals; D000831:Animals, Newborn; D003287:Contrast Media; D003911:Dextrans; D004195:Disease Models, Animal; D006801:Humans; D007051:Ibotenic Acid; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D054220:Malformations of Cortical Development / Q000139:chemically induced* / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009498:Neurotoxins; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D009498:Neurotoxins; C097921:ferumoxtran-10; D007051:Ibotenic Acid
J Magn Reson Imaging. 2008 Oct;28(4):1046-52
18821607
Cerebrovasc Dis. 2007;24(6):544-6
18042981
AJNR Am J Neuroradiol. 1999 Feb;20(2):223-7
10094342
AJNR Am J Neuroradiol. 2006 May;27(5):1000-5
16687532
AJNR Am J Neuroradiol. 2005 Oct;26(9):2290-300
16219835
NMR Biomed. 2002 Jun;15(4):278-83
12112610
Neuropathology. 2002 Sep;22(3):106-32
12416551
Magn Reson Med. 2004 Aug;52(2):403-6
15282824
J Cereb Blood Flow Metab. 2007 Dec;27(12):1941-53
17440490
J Neuropathol Exp Neurol. 1995 May;54(3):358-70
7745435
AJNR Am J Neuroradiol. 2003 May;24(5):805-9
12748075
Stroke. 2007 Feb;38(2):303-7
17170357
Radiology. 1997 Jan;202(1):25-9
8988186
Invest Radiol. 2004 Jan;39(1):56-63
14701989
Magn Reson Med. 1999 Feb;41(2):329-33
10080281
MAGMA. 1999 Aug;8(3):185-9
10504046
Brain Pathol. 2001 Jan;11(1):56-71
11145204
J Magn Reson Imaging. 1994 May-Jun;4(3):301-7
8061425
Radiographics. 2004 May-Jun;24(3):867-78
15143236
Stroke. 2007 Jan;38(1):131-7
17122417
Eur J Paediatr Neurol. 1998;2(6):313-8
10727198
J Neuroimmunol. 2008 Mar;195(1-2):1-6
18177950
Adv Drug Deliv Rev. 2006 Dec 1;58(14):1471-504
17116343
Invest Radiol. 1999 Nov;34(11):722-7
10548385
Radiology. 2008 Jul;248(1):114-23
18458246
NMR Biomed. 2006 Feb;19(1):101-7
16411166
Arch Neurol. 2008 Oct;65(10):1291-5
18852342
Stroke. 2007 Oct;38(10):2733-7
17717318
NMR Biomed. 2004 Jun;17(4):163-9
15229929
J Magn Reson Imaging. 1999 Feb;9(2):291-4
10077027
Kidney Int. 2001 Feb;59(2):764-73
11168960
Brain. 2004 Mar;127(Pt 3):616-27
14691063
Magn Reson Med. 2003 Aug;50(2):309-14
12876707
Brain. 2004 Jul;127(Pt 7):1670-7
15128622
Brain. 2008 Mar;131(Pt 3):800-7
18245785
Eur Radiol. 2002 May;12(5):1104-13
11976854
Lancet Oncol. 2006 Jan;7(1):52-60
16389184