fig1

Figure 1. Preoperative angiography. Left ICA (A) and right ICA (B) angiography revealed a bilateral moyamoya disease. Vertebral angiography showed stenosis at proximal segment of right PCA and pooly developed left PCA, suggesting posterior circulation involvement (C). The anterior-posterior (B) and coronal (D) view of right ICA showed a watershed between parietal and occipital lobe, where there was lack of moyamoya collaterals from both anterior and posterior circulation (white arrow). ICA: internal carotid artery; PCA: posterior cerebral artery