NCCT: Decreased attenuation with loss of grey white matter differentiation and effacement of the adjacent sulci involving bilateral ACA and MCA territories.
Bilateral frontal horns of lateral ventricles are also effaced.
CTA: Absence of flow in the right internal carotid artery from its extracranial portion (C1 segment, Bouthillier classification) and absence of flow in the left internal carotid artery in its terminal segment, preservation of arterial flow from the anterior region of the temporal lobe through collateral arteries