Fig. 2.

Permeability signatures and their correlation to hemorrhagic transformation illustrated in combined basal ganglia and cortical infarcts. Diffusion-weighted images, k_trans maps, and susceptibility-weighted images of three representative patients are displayed. In the first row, diffusion restriction in the right striatum and adjacent cortex is seen with focal k_trans increase in the right striatum, but no hemorrhagic transformation (a). In the second row, diffusion restriction in the left BG and a small portion of the insular cortex as well as in the temporal cortex is evident. Diffusion restriction co-localizes with increased k_trans and hemorrhagic infarction type 2 in the caudate head in the striatum and the insular cortex. (b) In the third row, diffusion restriction is seen in the right striatum and the adjacent cortex with increased k_trans and parenchymal hemorrhage type 1 in the striatum as well as petechial hemorrhages in the insular cortex (c). Patients without hemorrhagic transformation displayed a significantly lower k_trans compared to patients with hemorrhagic infarction type 2 or parenchymal hemorrhage type 1 (d). A moderate correlation of early clinical outcome and k_trans values was apparent (e)