title: Simple new technique for sonographic measurement of the thyroid in neonates and small children.
abstract: OBJECTIVE
  The aim of this study was to determine whether the ratio of the thyroid width (Th) to the trachea width (Tr) is a useful technique for sonographic estimation of thyroid size in neonates and small children.
  
  
  METHODS
  We prospectively performed sonographic examination of the thyroid gland in 30 pediatric subjects ranging in age from 1 week to 12 years. The sum of the maximum width of the left thyroid lobe and the maximum width of the right lobe was considered the Th. Each subject's thyroid was classified as small, normal sized, or large on the basis of the Th value in reference to the subject's body height. The ratios of the Th to the Tr were then calculated and compared among the 3 groups by 1-way analysis of variance. Correlation and regression analyses were performed to determine the correlation between body height and Tr. A p value of less than 0.05 was considered significant.
  
  
  RESULTS
  The mean Th/Tr ratios (+/- standard deviations) for the 3 groups were as follows: small, 1.25 +/- 0.19; normal sized, 2.09 +/- 0.19; and large, 4.10 +/- 2.42. The difference in the Th/Tr ratios between the 3 groups was statistically significant (p < 0.0001). A significant positive correlation was found between Tr and body height (p < 0.001; r = 0.85).
  
  
  CONCLUSIONS
  The Th/Tr ratio is a simple, practical parameter for estimating the size of the thyroid gland in neonates and small children.
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Yasumoto
authors.forename: Hideaki
authors.initials: H
authors.lastname: Inoue
authors.forename: Isamu
authors.initials: I
authors.lastname: Ohashi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shibuya
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Onishi
mesh_terms: D000886:Anthropometry; D001827:Body Height; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D013961:Thyroid Gland / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods / Q000706:statistics & numerical data