title: Inter- and intra-observer variation of fetal volume measurements with three-dimensional ultrasound in the first trimester of pregnancy.
abstract: To determine the inter- and intra-observer variation of volume calculations of human fetuses at a gestational age of 11(+0)-13(+6) weeks by three-dimensional ultrasound (3DUS).
  
  
  
  3DUS datasets were acquired during nuchal translucency measurements. The fetal volume (FV) was measured in 65 cases by two independent investigators. The Virtual Organ Computer aided AnaLysis (VOCAL™) imaging software was used to manually calculate the FV (rotational angle 9°). Inter- and intra-observer variation were assessed by Bland-Altman plots and intraclass correlation coefficients (ICC).
  
  
  
  Both inter- and intraobserver reproducibility were highly reliable as shown by the Bland-Altman plots and an ICC of respectively 0.934 and 0.994.
  
  
  
  FV calculation by 3DUS with VOCAL and a rotational angle of 9° is feasible and has a high inter- and intraobserver reliability in the first trimester of pregnancy.
authors: Department of Gynecology and Obstetrics, Atrium Medical Center, Parkstad, The Netherlands. nss06@atriummc.nl
authors: Nicol A C
authors: NA
authors: Smeets
authors: Joost
authors: J
authors: van de Ven
authors: S Guid
authors: SG
authors: Oei
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000706:statistics & numerical data; D015588:Observer Variation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D015203:Reproducibility of Results; D012984:Software; D016216:Ultrasonography, Prenatal / Q000379:methods* / Q000706:statistics & numerical data; D055815:Young Adult