Purpose: Intracranial atherosclerosis is a common condition in Korean population consisting over 25% of ischemic stroke etiology. American Stroke Association and Korean Stroke Society recommend antiplatelet and statin for the treatment of intracranial atherosclerosis. Besides lowering blood cholesterol levels statin also stabilize atherosclerotic plaque and eventually lower the risk of ischemic stroke. However, little evidence resides on the effect of statin treatment on intracranial atherosclerosis. Recent advance in high-tesla magnetic resonance imaging enables direct imaging of intracranial atherosclerotic plaque and further assessment of treatment efficacy of statin in stabilization of intracranial atherosclerotic plaque became possible.

Inclusion Criteria:

• Acute ischemic stroke patients within 7 days of symptom onset
• Symptomatic intracranial artery stenosis (above 30%) at proximal portion of middle cerebral artery (MCA), basilar artery, or intracranial portion of intracranial artery (ICA).
• Not receiving statins (HMA-coA reductase)
• Willing and able to comply with scheduled visits, lifestyle guidelines, treatment plan, laboratory tests, and other study procedures.

Exclusion Criteria:

• Extracranial artery (carotid artery bifurcation, proximal vertebral artery) stenosis above 50%
• Stroke attributable to cardioembolic origin (atrial fibrillation, valvular heart disease, aortic arch atherosclerosis)
• Severe hepatic or renal dysfunction
• Pregnant females as determined by positive urine hCG test or lactating females
• Subjects considered unwilling or unable to comply with the imaging procedures and study visit schedule