Purpose or Case Report: Moyamoya disease (MMD) is an uncommon cerebrovascular disease that is characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches, which is accompanied by the development of collateral vessels at the base of the brain. The purpose of this educational exhibit is to provide a succinct review of the imaging findings of MMD and its frequently associated complications, demonstrate the role of various imaging techniques in diagnosis and clinical decision making, and give an overview of surgical approaches and post operative appearances.
Methods & Materials: This exhibit will provide an overview of the imaging appearances of MMD. We will discuss the role of hyperintense vessels on fluid-attenuated inversion recovery images (Ivy sign) and their contribution to the evaluation of collateral patterns in MMD patients. Additionally, this exhibit will illustrate the common collateral patterns of MMD assessed by conventional catheter and MR angiography and the associations of these angiographic vascular patterns with cerebrovascular lesions, including ischemia and hemorrhage. An overview of Suzuki staging for MMD will be provided. Role of advanced techniques such as MR Angiography and MR Perfusion in clinical decision making will be discussed.
Results: The clinical manifestations of Moyamoya are variable and include transient ischemic attack (TIA), ischemic stroke, hemorrhagic stroke, and epilepsy. MR Angiogram provides a non-invasive visualization of the status on intracranial vasculature and is especially useful for assessment of the degree of stenosis of the internal carotid artery and the presence of collateral flow. MRI of the brain provides information about the status of brain parenchyma and rules out intracranial infarction or ischemia. MR perfusion provides a powerful imaging modality to assess tissue perfusion parameters that provide clinically useful information to assess the need for revascularization.
Conclusions: MRI with Angiogram and MR perfusion imaging provides a robust imaging modality that qualitatively as well as quantitatively analyzes the status of brain parenchyma, assessment of vascular inflow to the brain, and relative degree of ischemia or vascular perfusion of the cerebral hemispheres. When combined with clinical judgement, this modality can be considered as the `one-stop-shop` for clinical decision making and assessing the need for revascularization surgery.