Eligibility CriteriaINCLUSION CRITERIA:
Men and women age 18 years or older admitted for angioplasty with or without stenting of any intra or extra-cranial vessel.
Any MRI contraindication (insulin pump, aneurysm clips, implanted neural stimulator, cardiac pacemaker or defibrillator, cochlear implant, metal shrapnel or bullet)
Patients with hyperperfusion syndrome following the angioplasty.
Patients with cardiovascular or respiratory instability.
Patients with severe peri-procedural stroke at risk for herniation.
Confused or encephalopathic patients who are unable to cooperate.