Purpose: To clarify the angiographic findings of the posterior circulation in patients with moyamoya disease.
Materials and methods: Seventy-six patients with idiopathic moyamoya disease were studied with conventional angiography. The angiographic findings were reviewed for steno-occlusive lesions, collateral vessels, and aneurysms and compared with the finding of parenchymal lesions on computed tomographic and magnetic resonance images.
Results: Of 152 posterior cerebral arteries (PCAs), 66 (43%) had a stenotic or occluded lesion. The frequency of PCA lesions statistically significantly increased with the extent of the internal carotid artery (ICA) bifurcation steno-occlusive lesion. As the severity of ICA stenosis increased, basal cerebral moyamoya vessels and transdural collateral vessels similarly increased in number, but leptomeningeal collateral vessels decreased owing to the progressive development of more PCA lesions. Cerebral infarctions, ventricular dilatation, and cerebral atrophy were found to increase in frequency in patients with steno-occlusive PCA lesions.
Conclusion: Steno-occlusive lesions of the PCA increase in frequency proportionally with severity of ICA bifurcation steno-occlusive lesions, so that cerebral infarctions increase in frequency with the extent of the PCA lesions.