[MRI findings of moyamoya disease in children].

Magnetic resonance imaging (MRI) findings were evaluated in two cases with moyamoya disease. A twelve-year-old girl and a five-year-old boy were admitted to our hospital with the complaints of transient ischemic attack. They were diagnosed as having moyamoya disease by cerebral angiogram. MRI clearly presented cerebral infarction by T2-weighted imaging and multiple small round or tortuous hypo_signal areas around the basal ganglia by proton density weighted imaging. These findings were consistent with moyamoya vessels shown by cerebral angiogram. Moyamoya vessels were visualized more clearly on proton density weighted imaging than on T1-weighted imaging. MRI is less invasive than cerebral angiogram and repeated safely. It might play an important role in a follow-up study of morphological changes on moyamoya vessels.