1. From the Department of Radiology (M.P.M., M.J., M.L.M., H.M.D.), Stanford University Medical Center, California; Our Lady of Lourdes Regional Medical Center (J.C.W.), Lafayette, La; Borgess Medical Center (F.A.-A.), Kalamazoo, Mich; and St Josephs Hospital (J.J.C.), Tampa, Fla.