From the Departments of Radiology (M.M.-B., D.K.H., W.A.C., D.S.H., C.Y.), Neurology (K.J.B., D.L.T., C.A.-L.), Neurosurgery (M.R.L.), and Surgery (T.H.), University of Washington, Seattle, WA; Department of Neurology, University of Utah, Salt Lake City (A.d.H.); and Department of Radiology, University of California-San Francisco (M.D.A.). (At 2016-07)