FIG 5. Occlusion/nonfilling of frontal lobe veins. A, Multiple large branches from the frontal (arrows) and temporal lobes coalesce to form a large SMCV trunk. B, Early venous phase shows no filling of veins and oligemic region of brain (arrow). C, During the late venous phase, the cortical veins (arrow) of the frontal lobe also fail to fill. D, CT scan shows deep frontal lobe and subcortical white matter edema. The attenuation of the cortical gray matter appears to be normal. The arterial structures are intact.