title: Reference range for fetal interventricular septum area by means of four-dimensional ultrasonography using spatiotemporal image correlation.
abstract: OBJECTIVE
  To determine reference range for fetal interventricular septum area by means of 3-dimensional ultrasonography (3DUS) using the spatiotemporal image correlation (STIC) method.
  
  
  METHODS
  A prospective, cross-sectional study was conducted on 328 normal pregnant women between the 18th and 33rd gestational weeks. To obtain the interventricular septum area, a virtual plane was used, with the green line (region of interest) adjacent to the external margin of the septum, which was manually delimited. To evaluate the correlation of the septum area with the gestational age, different regression modes were evaluated. The intraclass correlation coefficient was used to evaluate the interobserver reproducibility.
  
  
  RESULTS
  The interventricular septum area showed correlation with the gestational age (r = 0.81). The mean increased from 0.47 ± 0.10 cm² in the 18th week to 2.42 ± 1.13 cm² in the 33rd week of gestation. The mathematical equation that best represented this correlation was provided by linear regression: interventricular septum area = 0.0511 × gestational age (R² = 0.095). The interobserver reproducibility was good, with bias of 0.01 cm², precision of 0.07 cm² and absolute limits of agreement of -0.14 and +0.15 cm².
  
  
  CONCLUSIONS
  Reference range for fetal interventricular septum area were determined by means of 3DUS using STIC in the rendering mode and were shown to be reproducible.
authors.affiliation: Fetal Cardiology Unit, Department of Obstetrics, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
authors.forename: Luciano Marcondes Machado
authors.initials: LM
authors.lastname: Nardozza
authors.forename: Liliam Cristine
authors.initials: LC
authors.lastname: Rolo
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: Rodrigo
authors.initials: R
authors.lastname: Ruano
authors.forename: Antonio Fernandes
authors.initials: AF
authors.lastname: Moron
mesh_terms: D000465:Algorithms; D001938:Brazil; D003430:Cross-Sectional Studies; D019561:Echocardiography, Four-Dimensional; D005260:Female; D005865:Gestational Age; D006785:Hospitals, University; D006801:Humans; D016014:Linear Models; D009775:Obstetrics and Gynecology Department, Hospital; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D062211:Spatio-Temporal Analysis; D016216:Ultrasonography, Prenatal; D054088:Ventricular Septum / Q000000981:diagnostic imaging / Q000196:embryology*