1. From the Department of Radiology, Division of Emergency Radiology, Massachusetts General Hospital, 55 Fruit St, Blake SB Rm 0029A, Boston, MA 02114 (Shervin Kamalian, L.A., M.H.L., P.W.S., Shahmir Kamalian); and Department of Radiology, Massachusetts Eye and Ear Infirmary, Boston, Mass (H.D.C.).