[Repeated, reversible MR angiographic findings in pediatric moyamoya disease: case report].

The authors report a 6-year-old girl presented with headache and transient ischemic attack due to moyamoya disease. MR angiography (MRA) revealed that her symptoms were closely related to reversible deterioration of stenosis in the left middle cerebral artery (MCA). Deterioration of stenosis led to a decreased flow signal in the distal branches of the left MCA. MRA could also detect reversible stenotic changes in the right MCA, although she did not develop any neurological symptom. Although precise mechanism of reversible MR angiographic findings is still unknown, the phenomenon may play an important role in disease progression in pediatric patients with moyamoya disease.