A MODEL TO PREDICT THE HISTOPATHOLOGY OF HUMAN STROKE USING DIFFUSIONAND T-2-WEIGHTED MAGNETIC-RESONANCE-IMAGING

Background and Purpose We sought to identify MRI measures that have hi gh probability in a short acquisition time to predict, at early time p oints after onset of ischemia, the eventual development of cerebral in farction in clinical patients who suffer occlusion of a cerebral arter y. Methods We developed an MR tissue signature model based on experime ntally derived relationships of the apparent diffusion coefficient of water (ADC(W)) and T-2 to ischemic brain tissue histopathology. In eig ht stroke patients we measured ADC(W) and T-2 intensity using diffusio n-weighted echo-planar imaging (DW-EPI). Tissue signature regions were defined, and theme maps of the ischemic focus at subacute time paints after stroke onset were generated. Results Five MR signatures were id entified in human stroke foci: two that may predict either cell recove ry or progression to necrosis, one that may mark the transition to cel l necrosis, and two that may be markers of established cell necrosis. Conclusions An MR tissue signature model of ischemic histopathology us ing ADC(W) and T-2 can now be tested for its potential to predict reve rsible and identify irreversible cellular damage in human ischemic bra in regions.