Cerebral Arterial Variations Associated with Moyamoya Disease Diagnosed by MR Angiography.

Moyamoya disease is a rare progressive cerebrovascular steno-occlusive disease associated with different variations of the cerebral arteries. We evaluated the types and prevalence of such variations among patients with moyamoya disease. In our institution during the past seven years, we diagnosed 72 patients (24 male, 48 female; aged 6 to 75 years, mean, 42 years) with moyamoya disease by magnetic resonance (MR) angiography using either a 3-Tesla or one of two 1.5-T imagers and a standard time-of-flight technique without contrast media. An experienced neuroradiologist retrospectively reviewed the images. There were 15 cerebral arterial variations in 13 of 72 patients with moyamoya disease (18.1%), including four basilar artery fenestrations, three ophthalmic arteries arising from the middle meningeal artery, two intracranial vertebral artery fenestrations, two persistent first cervical intersegmental arteries, two persistent trigeminal arteries, one extracranial origin of the posterior inferior cerebellar artery, and one persistent stapedial artery. Although our number of patients was small, moyamoya disease was frequently associated with variations of the cerebral arteries, especially fenestrations in the vertebrobasilar system and persistent trigeminal artery.