2016 Volume 27 Issue 2 Pages 307-312
Moyamoya disease is a chronic, occlusive cerebrovascular disease of unknown ethology characterized by bilateral steno-occlusive changes at the terminal portion of the internal carotid artery and an abnormal vascular network at the base of the brain. In Japan, patients with moyamoya disease who meet the diagnostic criteria established by the Research Committee on Spontaneous Occlusion of the Circle of Willis (Moyamoya Disease) of the Ministry of Health and Welfare can receive full reimbursement of their medical expenses from the government. As such, the diagnostic criteria are extremely important. In the 2015 revision of the diagnostic criteria, recognition of flow voids of the sylvian valley, which is a characteristic finding in moyamoya disease, was added to the criteria. Microbleeds on T2* weighted imaging and the ivy sign on fluid-attenuated inversion recovery (FLAIR) imaging are well-known characteristic findings. Cortical and subcortical hyposignals on T2* weighted imaging and white matter hyperintensities on FLAIR imaging are valuable in evaluating ischemic findings. For evaluation of cerebral blood flow during the perioperative period in moyamoya disease, arterial spin labeling has contributed to the detection of hyperperfusion syndrome. In future work, we hope to promote imaging analysis to further our understanding of the pathophysiology of moyamoya disease.
