Histopathological correlations of nuclear magnetic resonance imaging parameters in experimental cerebral ischemia

Changes in the nuclear magnetic resonance (NMR) parameters of spin-lattice relaxation ( T 1), spin-spin relaxation ( T 2), proton density (ϱ), and water diffusion ( D NMR) were measured over time together with the histopathological status in three regions of rat brain cortex after permanent middle cerebral artery occlusion (MCA-O). Histological response ranged from severe irreversible damage (necrosis and cavitation) to relatively mild and apparently reversible damage. D NMR was the only NMR parameter which demonstrated a statistically significant change in all three regions of brain studied. Additionally, ϱ was significantly increased only in the region of brain studied which eventually progressed to necrosis and cavitation. Finally, data are presented which indicate that changes in T 2, D NMR, and ϱ can occur independently of one another.