3-D FETAL ECHOCARDIOGRAPHY IN VENTRICULAR SEPTAL DEFECTS

Purpose: The purpose of this study was to investigate the feasibility of a new three-dimensional imaging technique to reconstruct and display the site and spatial orientation of ventricular septal defects as part of a complex cardiac anomaly in fetuses and to determine whether any advantage is offered by this three-dimensional evaluation over conventional fetal echocardiography.

Methods and Materials: After 2-D fetal echocardiographic examination 3-D multiplanar datasets of the beating fetal heart using Spatio-Temporal Image Correlation (STIC) were collected prospectively in 23 fetuses with various types of vemtricular septal defects involving any part of the different portions of the interventricular septum. Basic echocardiographic key views of the venoatrial, atrioventricular and ventriculoarterial connections were derived from the data volume sets and selected for 2-D and 3-D analysis. Comparisons were made with conventional 2-D real-time echocardiographic imaging and the diagnostic image quality of interventricular and interatrial details were evaluated.

Results: The underlying cardiac malformation was well or satisfactorily visualized in 22 fetuses using 2-D imaging. 3-D data sets enabled diagnostically acceptable visualization of all affected cardiac stuctures in 7 of 23 fetuses. A 3-D reconstruction of the site and spatial orientation of the different defectious portions of the interventricular septum could be obtained in 13 patients.

Conclusions: Three-dimensional imaging of ventricular septal defects is feasible in a wide range of fetal cardiac lesions, and may provide additional information of clinical value when compared with 2-D imaging. 2-D imaging remained the principal diagnostic modality in all cases with additional strucutral detail obtained by 3-D imaging in 4 fetuses.