title: Thyroid heterogeneity, as indicated by the CV of ultrasonographic intensities, correlates with anti-thyroid peroxidase antibodies in euthyroid Hashimoto's thyroiditis.
abstract: OBJECTIVE
  To prospectively evaluate the heterogeneous appearance of the thyroid gland, reflecting inflammation and destruction in euthyroid Hashimoto's thyroiditis (HT), we investigated the clinical utilities of the heterogeneity index (HI) [the coefficient of variance (CV) of the ultrasonographic (US) intensities], focusing on anti-thyroid peroxidase antibodies (TPO-Ab), which represent not only disease activity but also subsequent thyroid destruction of HT.
  
  
  METHODS
  Forty-four consecutive patients with euthyroid HT [60.5 ± 2.7 years old (mean ± SE)] and 30 age-matched normal controls were studied. HI was calculated as the CV (SD/mean) of US intensities of either four points per lobe of the thyroid gland along a horizontal line at the depth of the right common carotid artery. Evaluation included serum levels of free thyroxine (FT4), free triiodothyronine (FT3), thyroid stimulating hormone (TSH), anti-thyroid peroxidase antibodies (TPO-Ab), anti-thyroglobulin antibodies (Tg-Ab), thyroglobulin and thyroid volume.
  
  
  RESULTS
  While no differences were observed for TSH, FT4 and FT3, thyroglobulin and thyroid volume between the two groups, HI exhibited a tendency towards a significant difference (3.59 ± 0.20% in HT patients vs 3.23 ± 0.19% in normal group, p = 0.089). In HT patients, there was a significant and positive correlation of HI with TPO-Ab (r = 0.396, p = 0.034), whereas such a correlation was absent in normal controls. In both groups, there were no significant correlations of HI with Tg-Ab, FT3, FT4 or TSH.
  
  
  CONCLUSIONS
  This is the first report of the close relation between heterogeneity of US of the thyroid gland and TPO-Ab in euthyroid HT patients before the heterogeneity becomes distinguishable from normal thyroid glands. Furthermore, at this stage, subsequent thyroid destruction in HT might be already be predicted through the heterogeniety of the thyroid tissue.
authors.affiliation: Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka-city 545-8585, Japan. toshi-n@jg7.so-net.ne.jp.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Wakita
authors.forename: Toshiki
authors.initials: T
authors.lastname: Nagasaki
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nagata
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Imanishi
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Yamada
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yoda
authors.forename: Masanori
authors.initials: M
authors.lastname: Emoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Ishimura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Inaba