Dynamic free-hand three-dimensional fetal echocardiography gated by cardiotocography

Abstract

Objective: To evaluate the clinical feasibility of conventional cardiotocography (CTG) as a cardiac cycle triggering signal for three-dimensional (3D) fetal echocardiography. Method: Free-hand 3D echocardiography was performed on a total of 25 fetuses with and without congenital heart disease at various gestational ages (mean, 29 weeks; range, 19-35 weeks). Simultaneously, online CTG was used for time gating. Gray-scale and color Doppler dynamic 3D displays, as well as multiplanar views, were assessed for their ability to depict the cardiac morphology and correct cardiac gating. Results: Valid CTG-based trigger signals could be obtained in 24 of the 25 fetuses. Correct cardiac gating was achieved in 101 of the 111 (91%) 3D datasets. Color Doppler imaging of blood flow in four dimensions was possible in 34 of 36 (94%) datasets. Reconstructed 3D and multiplanar views provided additional views not available in two-dimensional (2D) imaging. Acoustic interference between the CTG transducer and echotransducer could be reduced by the use of a high-frequency echotransducer, second-harmonic frequency imaging and appropriate positioning of the two transducers. Imaging quality was highly dependent on the quality of 2D images and random motion artifacts. Conclusions: CTG can be used as an online gating source for dynamic 3D fetal echocardiography. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.