The investigators performed a study on thirty patients with acute stroke of the middle cerebral artery using technetium-99m-DTPA brain SPECT (4). Tc-99m-DTPA (Diethylenetriamine- pentacetic acid) brain scintigraphy is a useful technique for the assessment of BBB disruption. Is has been used in the past to localize areas within the cranium which had been disrupted by infection, neoplasms, trauma or stroke. The study showed that the magnitude of disruption of the BBB was negatively correlated with the change in neurological status with a sensitivity of 95% and a specificity of 89%. Interestingly, a significant proportion of patients with stroke (23%) had no gross evidence of BBB disruption, all of them with very good prognosis.