Moyamoya disease (MMD) is an idiopathic progressive narrowing of distal internal carotid arteries and secondary development of small collaterals.(1) The distinction between MMD and intracranial atherosclerosis is not easy when a patient has concomitant vascular risk factors. We attempted to differentiate the 2 disease conditions by applying high-resolution plaque MRI in the occluded segment.(2) High-resolution MRI of MMD disclosed blunted obliteration of the vessel lumen without eccentric plaque, and black-blood image delineated the occlusion site with homogeneous material and multiple spring-like vascular structures (figure, A). Intracranial atherosclerosis showed eccentric plaque with heterogeneous signals and enhancement (figure, B).