Moya Moya Disease-MRI

Moya Moya is a rare idiopathic vasoocclusive disease characterized by progressive irreversible occlusion of main blood vessels to the brain as they enter into the skull. The occlusive process stimulates the development of an extensive network of enlarged basal, transcortical and transdural collateral vessels . In Japanese, Moya Moya means hazy. The disease derives its peculiar name from the angiographic appearance of cerebral vessels in the disease that resembles "puff of smoke". The process of blockage, once it begins tends to continue despite any known medical management unless treated with surgery.

MRI not only reveals areas of infarctions but also allows direct visualization of these collateral vessels as multiple small flow voids at the base of brain and basal ganglia. MR angiography is used to confirm the diagnosis and to see the anatomy of the vessels involved. It typically reveals the narrowing and occlusion of proximal cerebral vessels and extensive collateral flow through the perforating vessels demonstrating the classic puff of smoke appearance.

Our patient is 17 yr old female with history of recurrent seizures. MRI T1 weighted images show extensive collateralization of vessels in region of circle of willis. MRA reveals reduced luminal caliber of left internal carotid artery in petrous, cavernous and supraclinoid segments. Left MCA also shows attenuation of its luminal caliber when compared to its counterpart on right side along with collaterals at the base of the brain and basal gnaglia.