title: First trimester two- and four-dimensional cardiac scan: intra- and interobserver agreement, comparison between methods and benefits of color Doppler technique.
abstract: OBJECTIVE
  To evaluate intra- and interobserver agreement for first-trimester fetal cardiac structural assessment, using two-dimensional (2D) ultrasound (2D-US) and 4D-US (4D spatiotemporal image correlation (STIC) technology), to compare the methods and to assess the advantages of adding color Doppler to each technique.
  
  
  METHODS
  Digital videoclips (B-mode and color Doppler) and 4D-STIC volumes (gray-scale and color Doppler) from 632 pregnancies with normal fetal hearts were acquired and stored at the time of detailed first-trimester ultrasound examination. Later analysis on a randomized sample of 100 cases was performed, targeting 11 cardiac structures and features. We compared visualization of fetal heart parameters using 2D-US vs 4D-US and gray-scale vs color Doppler imaging.
  
  
  RESULTS
  STIC volumes were considered satisfactory (adequate visualization of at least 8/11 parameters) in 78% of cases and 2D-US acquisitions in 89% of cases. The intra- and interobserver agreement was good for both 2D and 4D methods (kappa > 0.6), and the percentage overall agreement was very high using both methods (95%). 2D- and 4D-US identification of the fetal cardiac parameters did not differ significantly. The differences between gray-scale and color Doppler imaging were statistically significant in identifying similar key cardiac parameters, for both 2D- and 4D-US (P < 0.05).
  
  
  CONCLUSIONS
  Both 2D and 4D methods for assessing first-trimester heart parameters are feasible and repeatable within and between observers. Color Doppler adds valuable information to both methods.
authors.affiliation: Prenatal Diagnostic Unit, Emergency University Hospital, Craiova, Dolj, Romania; University of Medicine and Pharmacy Craiova.
authors.forename: S
authors.initials: S
authors.lastname: Tudorache
authors.forename: M
authors.initials: M
authors.lastname: Cara
authors.forename: D G
authors.initials: DG
authors.lastname: Iliescu
authors.forename: L
authors.initials: L
authors.lastname: Novac
authors.forename: N
authors.initials: N
authors.lastname: Cernea
mesh_terms: D000328:Adult; D002306:Cardiac Volume; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods; D015150:Echocardiography, Doppler / Q000379:methods; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D019561:Echocardiography, Four-Dimensional / Q000379:methods*; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D015588:Observer Variation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D016216:Ultrasonography, Prenatal / Q000379:methods; D055815:Young Adult
keywords: STIC; color Doppler; fetal heart; first trimester of pregnancy; interobserver agreement; intraobserver agreement; spatiotemporal image correlation