1. From the Noninvasive Cardiovascular Imaging Program, Departments of Medicine and Radiology (V.L.M., S.D., R.B., M.F.D.C.), Division of Cardiovascular Medicine (V.L.M., S.D., R.B., M.F.D.C.), and Division of Nuclear Medicine and Molecular Imaging (M.N., C.R.F., M.G., J.H., J.K., S.D.), Brigham and Women's Hospital, Boston, MA.