Table 1.

Suzuki grading system adapted from [47].

Stage I	Narrowing of Terminal ICA
Stage II	Initiation of moyamoya vessels in basal carotid circulation, dilation of intracerebral arteries
Stage III	Intensification of moyamoya vessels, severe carotid stenosis, defection of ACA and MCA
Stage IV	Minimization of moyamoya vessels, defection of PCA
Stage V	Further reduction of moyamoya, disappearance of major cerebral arteries
Stage VI	Disappearance of moyamoya collaterals and ICA, cerebral blood supply comes from external carotid arteries via leptomeningeal anastomoses

ICA: Internal Carotid Artery; ACA: Anterior Cerebral Artery; MCA: Middle Cerebral Artery; PCA: Posterior Cerebral Artery.