title: Assessment of the thymic morphometry using ultrasound in full-term newborns.
abstract: OBJECTIVE
  The size of thymus is variable and depends on age of the individual. Thymus undergoes its maximum development at the time of birth, when it also has the greatest relative weight. The aim of our study was to compare the two ways of expressing the size of the newborns' thymus, the Thymus index and estimated volume of thymus.
  
  
  METHODS
  The examined group consisted of 212 full-term newborns from Slovakia, Europe. We estimated the length, width and thickness of the left and right lobes. We used these data to calculate the approximate volume of the thymus. We also expressed size of the thymus as a multiple of the transverse diameter of the cranial part of the thymus and the sagittal area of the larger lobe of the thymus, the so-called Thymus index. Bilateral differences in thymus lobes' sizes, as well as the thymus' sizes between sexes and among the newborns of different types of birth were also analysed.
  
  
  RESULTS
  Our results show that (1) the left thymus lobe is longer and thicker than the right lobe; (2) the Thymus index and the estimated volume of the thymus have a strong significant and positive correlation; (3) boys reach significantly higher values of the Thymus index than girls; and (4) when comparing the differences in the thymus size between the newborns born in two different ways (spontaneous and operatively), no significant difference was discovered.
  
  
  CONCLUSIONS
  Ultrasound examination is safe, effective and suitable for simple assessment of the thymus size, which has a great variability in children. In other hand, the use of the Thymus index in everyday clinical practice is limited due to different mean values in a number of studies.
authors: Institute of Histology and Embryology, Faculty of Medicine, Comenius University in Bratislava, Sasinkova 4, 811 08, Bratislava, Slovakia. ivan.varga@fmed.uniba.sk
authors: Ivan
authors: I
authors: Varga
authors: Alexandra
authors: A
authors: Uhrinova
authors: Frantisek
authors: F
authors: Toth
authors: Jana
authors: J
authors: Mistinova
mesh_terms: D000886:Anthropometry / Q000379:methods; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012016:Reference Values; D013950:Thymus Gland / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014463:Ultrasonography