1 From the Department of Mechanical Engineering, Massachusetts Institute of Technology (C.J.L.).
2 Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School (M. Selim).
3 Department of Orthopedics, Brigham and Women's Hospital, Harvard Medical School; Tissue Engineering and Regenerative Medicine, VA Boston Healthcare System (M. Spector).
4 Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School (E.H.L.).