1. From the Departments of Radiology (J.Z., J.T., J.S., A.S.) and Neurosurgery (M.P., M.B., A.C., J.B., E.K.O.), Icahn School of Medicine, 1 Gustave Levy Pl, New York, NY 10029; and Department of Bioengineering and Bioinformatics, Boston University, Boston, Mass (J.L.).