Table 1.

CTA evaluation scales in the diagnosis of BD.

Criteria	Lack of opacification of
Intracranial non-filling	ICA beyond the level of the anterior clinoid process VA beyond their dural penetration ICV, GCV and the straight sinus
10-point*	BA Right and left PCA-P2 Right and left ACA-A3 (pericallosal artery) Right and left MCA-M4 Right and left ICV GCV
7-point*	Right and left ACA-A3 (pericallosal artery) Right and left MCA-M4 Right and left ICV GCV
4-point*	Right and left MCA-M4 ** Right and left ICV

^*One point is noted for each nonopacified vessel in the late phase. Cerebral circulatory arrest is diagnosed with the score of 10, 7, or 4 points, accordingly;

^**according to the 4-point scale, opacification of 1 or 2 cortical branches of MCA on the same side does not exclude the diagnosis of cerebral circulatory arrest provided there is no opacification of ICVs.