Multifocal narrowing and dilation of intracranial vessels (initial presentation)

In this initial CT angiogram of the extra and intracranial circulation, extensive multifocal narrowing and dilation of the intracranial vessels are apparent predominantly on the posterior circulation (basilar artery and posterior cerebral arteries) as well as the proximal and distal middle cerebral arteries (but to a lesser degree). Both supraclinoid internal carotid arteries demonstrate multifocal mild-to-moderate stenoses. Both anterior and middle cerebral arteries and their branches demonstrate diffuse, moderate-to-severe multifocal stenoses alternating with focal dilation suggesting hemodynamic significance. The anterior communicating artery complex has a normal appearance. The visible intradural vertebral arteries, basilar artery, and both posterior cerebral arteries and their branches demonstrate diffuse, moderate-to-severe multifocal stenoses alternating with focal dilation suggesting hemodynamic significance. The middle portion of the basilar artery shows moderate-to-severe stenosis of about 9mm in length. (Contributed by Dr. Jose Biller.)