Evaluation the added transverse planes in normal fetal upper mediastinum by new color imaging technique in fetal echocardiography

Introduction: The current study aimed to assess the efficacy of a new scanning procedure in fetal cardiac screening by 6 planes in the upper mediastinum. Methods: This is a prospective study. 123 normal fetuses without extracardiac abnormalities or CHD were enrolled in this study totally. Two sonographers with similar experience were trained for one month about how to obtain the added planes. Sonographer A used Color Doppler combined with the radiant flow (Color-R-flow) while sonographer B used high definition flow imaging combined with the radiant flow (HD-R-flow) to display 6 planes in the upper mediastinum. The difference between these two color modalities in subgroups of different fetal positions (supine, prone, and lateral position) was also discussed. Results: HD-R-flow has higher detection rates of the 6 planes than Color-R-flow. The differences presenting for the left innominate vein and azygos vein (LIV and AzV) view, bilateral subclavian arteries (BSA) view, and the bilateral internal thoracic arteries (BITA) view were significant (P<0.01). The results also demonstrated that HD-R-flow showed significantly higher detection rates than the Color-R-flow for the LIV and AzV view and the BITA view of the fetuses in the supine and lateral position, and BSA view of fetuses in lateral position. Conclusion: The current study introduced an enhanced scanning procedure to assess vessels in the fetal upper mediastinum. A new color-imaging technique was used to better show tiny vessels. This has confirmed its value in showing a satisfactory detection rate for the 6 cardiac planes.