Neuroimaging diagnosis and the collateral circulation in moyamoya disease.

Moyamoya disease (MMD) is an uncommon cerebrovascular disease that is characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches, which is accompanied by the development of dilated, fragile collateral vessels at the base of the brain. This review will present different neuroimaging modalities for the diagnosis of MMD. Importantly, we will discuss the role of hyperintense vessels on fluid-attenuated inversion recovery images and their contribution to the evaluation of collateral patterns in MMD patients. Additionally, this review will summarize these common collateral patterns of MMD assessed by conventional cerebral angiography, and the associations of these angiographic collateral patterns with cerebrovascular lesions, including ischemia and hemorrhage will also be reviewed.