1. From the Departments of Radiology, Division of Interventional Neurovascular Radiology (A.M.M., R.T.H., C.C.P., T.E.L., P.M.M., C.F.D., V.V.H.), Neurological Surgery (R.T.H., C.F.D., V.V.H.), and Neurology (D.R.G.), University of California, San Francisco.