Ng F, Venkatraman V, Parsons M, et al. - Researchers undertook this prospective longitudinal analysis to assess the degree of variability in microstructural injury within and adjacent to areas recognized as infarcted tissue utilizing diffusion tensor imaging (DTI). They examined 18 patients who presented within 12 h of anterior circulation acute ischemic stroke and underwent CT perfusion at baseline followed by fluid-attenuated inversion recovery and DTI 1-month. Within both the infarct lesion and the peri-infarct tissue vs their homologous contralateral brain regions, they detected lower fractional anisotropy (FA) and higher mean diffusivity (MD) values. Between remote nonhypoperfused tissue and its contralateral homologous area, they identified no difference in FA and MD. Findings revealed the presence of a gradient of microstructural injury corresponding to the severity of ischemic insult within and beyond conventionally defined infarct boundaries. Re-assessment is justified for the traditional dichotomized notion of infarcted vs noninfarcted tissue broadly utilized in clinical research and in practice.