NECT shows no intracranial haemorrhage. No territorial hypodensity nor hyperdense artery (stroke window). Multiple lacunar infarctions (bilateral thalami, caudate nuclei). Moderate cortical atrophy. Dilated and elongated basilar artery. Calcified atheroma seen in cavernous segment internal carotid arteries and V4 segment of the right vertebral artery.
Perfusion study shows increased Tmax and MTT in the posterior circulation, with normal CBF and CBV.
CT angiogram reveals a dolichoectatic basilar artery occupying the left cerebellopontine angle, which bifurcates at the level of the third ventricle. Left internal carotid bifurcation appears dysplastic. At the cervical level, the right ICA has a retropharyngeal position, whereas the left is laterocervical.
No vascular occlusion, dissection or stenoses in either extra or intracranial segments.