title: Timing of thyroid ultrasonography in the etiological investigation of congenital hypothyroidism.
abstract: OBJECTIVE
  To describe the findings of thyroid ultrasonography (T-US), its contribution to diagnose congenital hypothyroidism (CH) and the best time to perform it.
  
  
  METHODS
  Forty-four patients with CH were invited to undergo T-US and 41 accepted. Age ranged from 2 months to 45 years; 23 patients were females. All were treated with L-thyroxine; 16 had previously undergone scintigraphy and 30 had previous T-US, which were compared to current ones.
  
  
  RESULTS
  At the current T-US, the thyroid gland was not visualized in its normal topography in 10 patients (24.5%); 31 T-US showed topic thyroid, 17 with normal or increased volume due to probable dyshormonogenesis, 13 cases of hypoplasia and one case of left-lobe hemiagenesis. One patient had decreased volume due to central hypothyroidism. Scintigraphy scans performed 3-4 years earlier showed 100% agreement with current results. Comparisons with previous T-US showed concordant results regarding thyroid location, but a decrease in current volume was observed in eight due to the use of L-thyroxine, calling the diagnosis of hypoplasia into question.
  
  
  CONCLUSIONS
  The role of T-US goes beyond complementing scintigraphy results. It allows inferring the etiology of CH, but it must be performed in the first months of life. An accurate diagnosis of CH will be attained with molecular study and the T-US can guide this early assessment, without therapy withdrawal.
authors.affiliation: Disciplina de Endocrinologia, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brasil.
authors.forename: Maria de Fátima
authors.initials: MF
authors.lastname: Borges
authors.affiliation: Disciplina de Endocrinologia, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brasil.
authors.forename: Nathalie de Almeida
authors.initials: NA
authors.lastname: Sedassari
authors.affiliation: Disciplina de Endocrinologia, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brasil.
authors.forename: Anelise de Almeida
authors.initials: AA
authors.lastname: Sedassari
authors.affiliation: Disciplina de Radiologia e Diagnóstico por Imagem, UFTM, Uberaba, MG, Brasil.
authors.forename: Luis Ronan Marquez Ferreira de
authors.initials: LRMF
authors.lastname: Souza
authors.affiliation: Disciplina de Endocrinologia, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brasil.
authors.forename: Beatriz Pires
authors.initials: BP
authors.lastname: Ferreira
authors.affiliation: Disciplina de Endocrinologia, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brasil.
authors.forename: Beatriz Hallal Jorge
authors.initials: BHJ
authors.lastname: Lara
authors.affiliation: Disciplina de Endocrinologia, Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brasil.
authors.forename: Heloísa Marcelina Cunha
authors.initials: HMC
authors.lastname: Palhares
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D013974:Thyroxine / Q000627:therapeutic use; D013997:Time Factors; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D013974:Thyroxine