Fig 6. Transit time effects. Axial T2-weighted image through the cavernous sinuses revealed absence of flow void in the right internal carotid artery (not shown), indicating slow flow or occlusion. Restricted diffusion is present, which is consistent with watershed infarct (arrow). ASL CBF map reveals decreased flow in the right posterior watershed zone as well as linear high signal intensity representing slow flow in cortical vessels (arrowheads).