1. From the Department of Radiology, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115 (D.M.R., C.B.B., P.M.D., E.A., M.C.F.); and Thyroid Program, Division of Endocrinology, Boston Children’s Hospital, Boston, Mass (A.J.W., C.E.C., J.R.S.).