ABSTRACT
This patient presented with stereotypic left carotid TIAs and had failed medical therapy. The left cervical carotid angiogram (A) demonstrates a 99% lesion, appropriate for surgery. There is also an “isolated” left MCA segment seen on the intracranial angiogram (B) which fills only from the affected left common carotid artery. The intracranial right carotid angiogram (C) shows robust filling but no crossover from right to left, presumably from a hypoplastic left A-1 segment.
