1. From the Department of Neurology (A.B., J.C., M.A., L.D., K.J., R.A.P., D.A.A., M.B., A.D., L.B.E., M.G., A.G.H., D.J.I., A.L., J.O.-M., C.C.Q., T.F.T., S.S.S., R.H.H., C.A.E.), Penn Statistics in Imaging and Visualization Center (PennSIVE) (R.T.S.), Department of Biostatistics, Epidemiology, and Informatics, and Center for Biomedical Image Computing and Analytics (R.T.S.), Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia.