First trimester two- and four-dimensional cardiac scan: intra- and interobserver agreement, comparison between methods and benefits of color Doppler technique

Ultrasound Obstet Gynecol. 2013 Dec;42(6):659-68. doi: 10.1002/uog.12459.


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).

Conclusion: 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.

Keywords: STIC; color Doppler; fetal heart; first trimester of pregnancy; interobserver agreement; intraobserver agreement; spatiotemporal image correlation.

Publication types

  • Comparative Study
  • Observational Study

MeSH terms

  • Adult
  • Cardiac Volume
  • Cohort Studies
  • Echocardiography / methods
  • Echocardiography, Doppler / methods
  • Echocardiography, Doppler, Color / methods*
  • Echocardiography, Four-Dimensional / methods*
  • Female
  • Fetal Heart / diagnostic imaging*
  • Gestational Age
  • Humans
  • Observer Variation
  • Pregnancy
  • Pregnancy Trimester, First
  • Ultrasonography, Prenatal / methods
  • Young Adult