1. From the Department of Diagnostic Imaging (E.L.T., R.A.M., G.L.B., E.L.D., D.T.H., G.A.T., M.V.J.), Neurology (R.A.M., S.Y., M.H., M.V.J.), and Neurosurgery (R.A.M., M.V.J.), Warren Alpert School of Medicine at Brown University Providence, RI; and Norman Prince Neuroscience Institute (R.A.M., S.Y., G.A.T., M.V.J.) and Lifespan Biostatistics Core (G.L.B.), Rhode Island Hospital.