title: The role of ¹²³I imaging in the evaluation of infants with mild congenital hypothyroidism.
abstract: OBJECTIVE
  Controversy exists regarding the diagnosis and treatment of mild congenital hypothyroidism (MCH). We studied the value of (123)I imaging in patients with MCH.
  
  
  METHODS
  Retrospective chart review of infants and children <4 years of age who underwent (123)I imaging: group 1 = MCH [thyroid-stimulating hormone (TSH) <25 µIU/ml, normal free T4/T3], group 2 = severe congenital hypothyroidism (TSH ≥25 µIU/ml), and group 3 = MCH in infancy imaged after treatment withdrawal at age 3 years. Data collected included 4- and 24-hour (123)I uptake, TSH, free T4/total T3 at imaging, age at imaging, and levothyroxine (L-T4) dose at 1 year of.
  
  
  RESULTS
  Thirty-six patients underwent (123)I imaging. In group 1 (n = 20, median TSH: 8.49 µIU/ml), 85% had abnormal imaging consistent with dyshormonogenesis. Two patients were referred after 1 year of age. The median age at imaging for the remaining 18 patients was 54 days. Median L-T4 dose at 1 year of age for these 18 patients was 2.8 μg/kg, which is consistent with dyshormonogenesis. Ninety-one percent of group 2 (n = 11, median TSH: 428.03 µIU/ml) had abnormal imaging. The median age at imaging was 13 days. Four patients in group 3 had abnormal (123)I imaging and restarted treatment.
  
  
  CONCLUSIONS
  (123)I imaging is a valuable tool for evaluation, diagnosis, and treatment of MCH.
authors.affiliation: Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Kravis Children's Hospital, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Evan
authors.initials: E
authors.lastname: Graber
authors.forename: Molly O
authors.initials: MO
authors.lastname: Regelmann
authors.forename: Rachel
authors.initials: R
authors.lastname: Annunziato
authors.forename: Josef
authors.initials: J
authors.lastname: Machac
authors.forename: Robert
authors.initials: R
authors.lastname: Rapaport
mesh_terms: D003409:Congenital Hypothyroidism / Q000097:blood / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007456:Iodine Isotopes / Q000008:administration & dosage; D008297:Male; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D050033:Thyroid Dysgenesis / Q000097:blood / Q000000981:diagnostic imaging*; D013963:Thyroid Hormones / Q000097:blood
chemical_list: D007456:Iodine Isotopes; D013963:Thyroid Hormones