title: Thyroid color flow Doppler sonography: an adjunctive tool for differentiating patients with inappropriate thyrotropin (TSH) secretion due to TSH-secreting pituitary adenoma or resistance to thyroid hormone.
abstract: BACKGROUND
  Thyrotropin (TSH)-secreting pituitary adenoma (TSHoma) and resistance to thyroid hormone (RTH) are two forms of inappropriate TSH secretion. Thyroid blood flow is largely TSH dependent.
  
  
  OBJECTIVE
  To assess whether thyroid blood flow may help to differentiate TSHoma and RTH.
  
  
  METHODS
  Intrathyroidal color flow Doppler sonography (CFDS) pattern and peak systolic velocity (PSV) were assessed at baseline and during T(3) suppression test on eight consecutive patients with TSHoma and 10 with RTH.
  
  
  RESULTS
  All controls had CFDS pattern 0. Three RTH patients had pattern I and seven had pattern II. Two TSHoma patients had pattern I, five had pattern II, and one had pattern III. PSV at baseline was 3.8 +/- 1.3 cm/s in controls, 8.8 +/- 2.5 cm/s in RTH, 11.1 +/- 2.7 cm/s in TSHoma (p < 0.0003 vs. controls, p = 0.087 RTH vs. TSHoma). After T3 suppression test, PSV values were lower in RTH than in TSHoma (4.6 +/- 1.8 vs. 7.7 +/- 2.6 cm/s, p = 0.008). PSV values and CFDS pattern normalized in nine and eight RTH patients, respectively, after T(3) suppression test; conversely, only one TSHoma patient had a normalization of PSV values, and none had a normalization of CFDS pattern (p < 0.003 vs. RTH).
  
  
  CONCLUSIONS
  Both RTH and TSHoma have increased CFDS pattern and PSV values; however, after T(3) both parameters normalized in most patients with RTH but not in those with TSHoma. Accordingly, CFDS pattern and PSV are adjunctive tools to differentiate these two forms of inappropriate TSH secretion.
authors.affiliation: Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy. f.bogazzi@endoc.med.unipi.it
authors.forename: Fausto
authors.initials: F
authors.lastname: Bogazzi
authors.forename: Luca
authors.initials: L
authors.lastname: Manetti
authors.forename: Luca
authors.initials: L
authors.lastname: Tomisti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rossi
authors.forename: Chiara
authors.initials: C
authors.lastname: Cosci
authors.forename: Chiara
authors.initials: C
authors.lastname: Sardella
authors.forename: Luigi
authors.initials: L
authors.lastname: Bartalena
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gasperi
authors.forename: Enrico
authors.initials: E
authors.lastname: Macchia
authors.forename: Paolo
authors.initials: P
authors.lastname: Vitti
authors.forename: Enio
authors.initials: E
authors.lastname: Martino
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D000368:Aged; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006964:Hyperpituitarism / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000378:metabolism*; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D013963:Thyroid Hormones / Q000502:physiology*; D013972:Thyrotropin / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
chemical_list: D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine