['carotid stenosis']
['ticlopidine + ginko biloba', 'clopidogrel']

        Inclusion Criteria:

          -  Patients scheduled for stent implantation due to carotid stenosis

          -  Patients resistant to clopidogrel defined by platelet inhibition rate <20% measured by
             Verify Now before carotid stenting

          -  Patients with informed consent

        Exclusion Criteria:

          -  Antiplatelet therapy other than aspirin, clopidogrel, or ticlopidine

          -  Unable to perform MRI scans

          -  Patients with hematologic abnormalities including neutrophil <1500/ul, platelet
             <100,000/uL, or AST/ALT >120 U/L

          -  Unsuitable for participation
      