Three-dimensional (3D) and 4D color Doppler fetal echocardiography using spatio-temporal image correlation (STIC)

Color Doppler echocardiography is used to visualize three transverse planes: the four-chamber, five-chamber, and three vessels and trachea views. Color Doppler spatio-temporal image correlation (STIC) is a new three-dimensional (3D) technique allowing the acquisition of a volume of data from the fetal heart that is displayed as a cineloop of a single cardiac cycle. The aim of the study was to examine the potential of color Doppler STIC to evaluate normal and abnormal fetal hearts.

This prospective study included 35 normal fetuses and 27 fetuses with congenital heart defects (CHD) examined between 18 and 35 weeks of gestation. Volume acquisition was achieved by initiating the image capture sequence from the transverse four-chamber view. Volumes were stored for later offline evaluation using a personal computer-based workstation in a multiplanar mode and as spatial volume rendering.

Successful acquisition was possible in all 62 cases. The three planes could be demonstrated in 31/35 healthy fetuses and in 24/27 fetuses with CHD. Spatial volume rendering was attempted in 18 fetuses with CHD. In the four normal fetuses with inadequate visualization using color Doppler STIC, the region of interest was perpendicular to the ultrasound beam. In two fetuses with CHD inadequate visualization was related to an enlarged heart in late gestation, in which the entire cardiac volume could not be acquired. The third case was an 18-week fetus with complex CHD and transposed great vessels in which artifacts were related to confluent color signals as a result of low resolution in the reconstructed plane.

STIC in combination with color Doppler ultrasound is a promising new tool for multiplanar and 3D/4D rendering of the fetal heart. Limitations may be found later in gestation in fetuses with large hearts and early in gestation as a result of low discrimination of signals. In addition, insonation perpendicular to the structure of interest does not image color Doppler signals and should be avoided during acquisition.