Comparison study of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography

To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities.

Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI.

Mean HI scores were higher than mean FI scores (2.73 +/- 0.43 vs 2.16 +/- 0.69, P < 0.001) for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73 +/- 0.43 vs 2.88 +/- 0.32, P < 0.001) and suboptimal (1. 65 +/- 0.41 vs 2.58 +/- 0.47, P < 0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 (P < 0.001).

harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.