Thomas A Gallagher1, Neil G Simon2, Michel Kliot2. 1. From the Departments of Radiology (T.A.G.) and Neurosurgery (T.A.G., M.K.), Northwestern University Feinberg School of Medicine, Chicago, IL; Prince of Wales Clinical School (N.G.S.), University of New South Wales; and Department of Neurology (N.G.S.), St. Vincent's Hospital, Darlinghurst, Australia. tgallagh@nm.org. 2. From the Departments of Radiology (T.A.G.) and Neurosurgery (T.A.G., M.K.), Northwestern University Feinberg School of Medicine, Chicago, IL; Prince of Wales Clinical School (N.G.S.), University of New South Wales; and Department of Neurology (N.G.S.), St. Vincent's Hospital, Darlinghurst, Australia.