1. Interventional Neuroradiology, The Johns Hopkins Hospital, Baltimore, Maryland
2. Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, Maryland
3. Cardiovascular Diagnostic Laboratory, The Johns Hopkins Hospital, Baltimore, Maryland
4. Department of Radiology and Radiological Sciences, Neurointensive Care Unit, The Johns Hopkins Hospital, Baltimore, Maryland
5. Department of Neurology and Cerebrovascular Surgery, The Johns Hopkins Hospital, Baltimore, Maryland