title: Reference ranges of atrioventricular valve areas by means of four-dimensional ultrasonography using spatiotemporal image correlation in the rendering mode.
abstract: OBJECTIVE
  This study aims to determine reference curves for fetal atrioventricular valve areas by means of three-dimensional ultrasound using the spatiotemporal image correlation (STIC) software.
  
  
  METHODS
  This was a cross-sectional prospective study on 328 normal fetuses between the 18th and the 33rd weeks of pregnancy. In order to obtain valve areas, the four heart chambers plane was used with the fetus in a dorsal posterior position. To construct reference ranges, a linear regression model was used, adjusted according to the coefficient of determination (R(2)). To calculate the reproducibility of the tricuspid valve area, the intraclass coefficient correlation (ICC) was used.
  
  
  RESULTS
  The mean areas of the tricuspid and mitral valves ranged from 0.19 ± 0.08 and 0.20 ± 0.10 cm(2) in the 18th week to 0.93 ± 0.31 and 1.06 ± 0.39 cm(2) in the 33rd week, respectively. The intra-observer and interobserver reproducibility was excellent with ICC = 0.997 and 0.933, respectively.
  
  
  CONCLUSIONS
  Reference curves for fetal atrioventricular valve areas were determined and presented good reproducibility.
authors.affiliation: Department of Obstetrics, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Liliam Cristine
authors.initials: LC
authors.lastname: Rolo
authors.forename: Luciano Marcondes Machado
authors.initials: LM
authors.lastname: Nardozza
authors.forename: Edward
authors.initials: E
authors.lastname: Araujo Júnior
authors.forename: Alan Roberto
authors.initials: AR
authors.lastname: Hatanaka
authors.forename: Luciane Alves
authors.initials: LA
authors.lastname: Rocha
authors.forename: Christiane
authors.initials: C
authors.lastname: Simioni
authors.forename: Antonio Fernandes
authors.initials: AF
authors.lastname: Moron
mesh_terms: D003430:Cross-Sectional Studies; D019561:Echocardiography, Four-Dimensional; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006351:Heart Valves / Q000000981:diagnostic imaging* / Q000196:embryology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000196:embryology; D011247:Pregnancy; D011446:Prospective Studies; D012016:Reference Values; D014261:Tricuspid Valve / Q000000981:diagnostic imaging / Q000196:embryology; D016216:Ultrasonography, Prenatal / Q000379:methods*