1 Department of Radiology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA.
2 Department of Neurology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA; Department of Neurosurgery, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA.
3 Department of Neurology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA.
4 Department of Radiology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA; Department of Neurology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA; Department of Neurosurgery, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA.