Neuroimaging assessment of memory-related brain structures in a rat model of acute space-like radiation.
J Magn Reson Imaging
; 29(4): 785-92, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19306400
ABSTRACT
PURPOSE:
To investigate the acute effects on the central nervous system (CNS) of (56)Fe radiation, a component of high-energy charged particles (HZE) in space radiation, using quantitative magnetic resonance imaging (MRI) noninvasively. MATERIALS ANDMETHODS:
Sprague-Dawley rats were exposed to whole-brain (56)Fe (0, 1, 2, and 4 Gy). At 1 week postirradiation, MRI scans were made using T2-weighted (T2WI), diffusion-weighted (DWI), and contrast enhanced T1-(CET1) imaging. T2 relaxation time and apparent diffusion coefficient (ADC) values were obtained from memory-related brain regions of interest (ROIs). Histopathology was correlated using ex vivo tissues.RESULTS:
No overt abnormalities were visualized using T2WI and DWI at 1 week postradiation. CET1 values did not differ significantly between the irradiated and control animals. Compared to 0 Gy, there were significant prolongations in T2 values and reductions in ADC after irradiation. In the absence of evident neuronal pathology, immunohistochemistry revealed astrocytic activation in 4 Gy animals.CONCLUSION:
At 1 week after whole-brain (56)Fe exposure, T2 and ADC values can differentiate radiosensitivity in regions critical for hippocampal-related memory. MRI may provide noninvasive assessment of the initial molecular/cellular disturbances in vivo after HZE irradiation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tálamo
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Imageamento por Ressonância Magnética
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Córtex Entorrinal
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Radiação Cósmica
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Hipocampo
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Isótopos de Ferro
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article