1. From the Departments of Neurology (D.J.J.W., J.R.A., Q.H., R.F., J.L.S., D.S.L.) and Radiology (D.J.J.W., J.R.A., J.X.Q., S.H., W.B.P., N.S.), University of California at Los Angeles, Los Angeles, CA; and the Institute for Medical Image Computing (M.G.), University of Bremen, Bremen, Germany.