Quantifying Collateral Perfusion in Cerebrovascular Disease-Moyamoya Disease and Stroke Patients

Inclusion Criteria: Moyamoya Patient Inclusion Criteria: * Men and non-pregnant women, at least 21 years of age. * Outpatients seen at the Stanford Neurosurgery and Neurology Departments. * Ability to comply with all studies. * Inclusion of Moyamoya patients with Sulfa allergies. * Patients diagnosed with or suspected to have Moyamoya disease. Stroke Patient Inclusion Criteria: * Men and non-pregnant women, at least 21 years of age. * Patients admitted to the inpatient Stanford Stroke Service for stroke-like symptoms, less than 24 hours from last time seen normal. * Ability to comply with all studies. Clinical Patient Acetazolamide MRI Inclusion Criteria: * Men and non-pregnant women, at least 21 years of age. * Patients admitted to the inpatient Stanford Stroke Service or Neurosurgical -Service for symptoms compatible with cerebrovascular disease. * Ability to comply with all studies. Normal Subject Inclusion Criteria: * Ability to comply with the MRI study. Exclusion Criteria: * Level of consciousness score of 2 or greater as defined by the NIH stroke scale. * Symptoms likely related to psychoactive drugs or patients with symptoms related to an active inflammatory disease such as AIDS, meningitis, or cerebritis. * Psychiatric or substance abuse disorder or dementia that interferes with evaluation or interpretation of the neurologic and mental assessment of these patients. * Informed consent cannot be obtained either from the patient or legal representative. * Severe coexisting or terminal systemic disease that limits life expectancy or that may interfere with the conduct of the study. * Symptoms related to an alternative diagnosis such as seizures or migraine. * Patients receiving any thrombolytic agent or receiving acute stroke investigational drug therapies during the 30-day study.