MR spectroscopic imaging and diffusion-weighted MRI for early detection of kainate-induced status epilepticus in the rat

Previous studies have shown that reduction of N-acetyl-aspartate (NAA) is correlated with the degree of neuronal loss at 3 days after kainate- induced status epilepticus in the rat. In this study, magnetic resonance spectroscopic imaging (MRSI), measurement of NAA and lactate, T₂-weighted MRI, and diffusion-weighted MRI were used to study early alterations in rat piriform cortex at 12 and 26 h after kainate administration. The major findings are that decreased NAA signal, increased lactate signal, and decreased apparent diffusion coefficient (ADC) were observed at 12 h, with little evidence of histological and T₂-weighted MRI changes. These results support the hypothesis that NAA, lactate signals, and ADC provide sensitive methods for detection of early and minimal brain damage in vivo.