Verification of Enhancement of the CSF Space, not Parenchyma, in Acute Stroke Patients with Early Blood—Brain Barrier Disruption

Enhancement on post-contrast fluid-attenuated inversion recovery (FLAIR) images after acute stroke has been attributed to early blood—brain barrier disruption. Using an estimate of parenchymal volume fraction and the apparent diffusion coefficient (ADC), we investigated the relative contributions of cerebral spinal fluid (CSF) and parenchyma to enhancement seen on postcontrast FLAIR. Enhancing regions were found to have low parenchymal volume fractions and high ADC values, approaching that of pure CSF. These findings suggest that contrast enhancement on FLAIR occurs predominately in the CSF space, not parenchyma.