title: [Tc99m-pertechnetate thyroid scintigraphy in newborns with congenital hypothyroidism].
abstract: BACKGROUND
  Congenital hypothyroidism is one of the most frequent endocrine diseases of the newborn and requires an early diagnosis to avoid its deleterious effects on neurological and intellectual functions.
  
  
  OBJECTIVE
  To evaluate thyroid scintigraphy (TS) findings in newborns with congenital hypothyroidism (CH), detected in the national program of newborn screening, which is working in Chile since 1992.
  
  
  METHODS
  TS findings of 189 newborns with CH (68% female) were analyzed. Tc99m pertechnetate TS was performed at 19 +/- 11 days of life. The gland was classified as eutopic, ectopic or absence of contrast (AC). Eutopic glands were classified by visual and quantitative criteria as: normal, goiter and decreased contrast (DC). TS results were compared by gender and hormonal levels.
  
  
  RESULTS
  Forty seven percent of newborns had ectopy, 29.1% eutopy and 24.3% AC. Eutopic gland predominated in males (44.2% vs 22.7%) and ectopy was more frequent in girls (53.1% vs 32.8%, p < 0.05). Newborns with AC had the most severe hormonal alterations, without gender differences. Newborns with normal TS had less hormonal alterations than those with goiter.
  
  
  CONCLUSIONS
  TS allows an etiological classification of CH. Thyroid dysgenesis is the most frequent cause, most of which correspond to ectopy, especially in girls. Eutopic glands are present in one third of newborns with CH. Goiter predominates, especially in males.
authors.affiliation: Unidad de Medicina Nuclear, CDT Hospital San Juan de Dios, Servicio de Pediatría, Hospital San Juan de Dios, Servicio de Salud Metropolitano Occidente, Ministerio de Salud, Chile. globo@machi.med.uchile.cl
authors.forename: Gabriel
authors.initials: G
authors.lastname: Lobo
authors.forename: David
authors.initials: D
authors.lastname: Ladrón de Guevara
authors.forename: Francisca
authors.initials: F
authors.lastname: Arnello
authors.forename: Andrés
authors.initials: A
authors.lastname: Pérez
authors.forename: Ximena
authors.initials: X
authors.lastname: Vivanco
authors.forename: Bernardo
authors.initials: B
authors.lastname: Bruggendieck
authors.forename: María Eliana
authors.initials: ME
authors.lastname: Bustos
authors.forename: César
authors.initials: C
authors.lastname: Jiménez
authors.forename: Gilda
authors.initials: G
authors.lastname: Donoso
authors.forename: Jorge
authors.initials: J
authors.lastname: Brantes
authors.forename: Carlos
authors.initials: C
authors.lastname: Becerra
mesh_terms: D002677:Chile; D003409:Congenital Hypothyroidism; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000000981:diagnostic imaging*; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m; D013961:Thyroid Gland / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m