1. From the Departments of Radiology, University of New Mexico, 2211 Lomas Blvd NE, Albuquerque, NM 87106 (H.G.H., J.F., L.K.); University of Washington School of Medicine, Seattle, Wash (J.D.G.); and University of Wisconsin School of Medicine and Public Health, Madison, Wis (J.P.K.).