High-resolution (< 50 microm) magnetic resonance imaging microscopy (MRM) has been used to identify brain regions and localization of excitotoxin-induced lesions in fixed rat brains, subsequently confirmed using standard histology. The anatomical extent of lesions identified by MRM was identical to that seen in histological sections and various histopathological changes could be visualized. In contrast to the time involved in preparing and examining histological sections, lesions in intact brains could be rapidly identified and visualized in three dimensions by examining digitally generated sections in any plane. This study shows that MRM has tremendous potential as a prescreening tool for neurotoxicity and neuropathology. These observations suggest that MRM has the potential to affect pathology much as conventional MRI has influenced clinical imaging.