Neuroimaging assessment of memory-related brain structures in a rat model of acute space-like radiation

Lei Huang, Anna Smith, Peter Cummings, Edward J. Kendall and Andre Obenaus
Journal of Magnetic Resonance Imaging 2009, 29, 785-792

The pupose of this study was to investigate the acute effects on the central nervous system (CNS) of ⁵⁶Fe radiation, a component of high-energy charged particles (HZE) in space radiation, using quantitative magnetic resonance imaging (MRI) noninvasively. Sprague-Dawley rats were exposed to whole-brain ⁵⁶Fe (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. At 1 week after whole-brain ⁵⁶Fe 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.