Figure 1.

Bone window computed tomography (CT) images illustrating the intracranial artery calcification score used. (A) CT scan showing thick, confluent calcification in both carotid siphons (score = 1 for each carotid artery. (B) CT scan showing thick, contiguous calcification in the right carotid artery (score = 1) and tiny, scattered calcification foci seen on only one slice in the left carotid artery (score = 0). (C) CT scan showing tiny, scattered calcification foci seen on at least two adjacent slices in the right middle cerebral artery (score 1) and tiny, scattered calcification foci seen on only one slice in the left middle cerebral artery (score = 0). (D) CT scan showing thick, contiguous calcification foci on both vertebral arteries (score 1 for each vertebral artery). (E) CT scan showing thick, interrupted calcification in the right vertebral artery (score = 1) and tiny, scattered calcification foci seen on only one slice in the left vertebral artery (score = 0). (F) CT scan showing thick, interrupted calcification in the basilar artery (score = 1). Arrows show calcification.