Objective: To establish the methodology for volumetric views of three-dimensional echocardiography (3DE) and to test the feasibility of the examination protocol in tetralogy of Fallot (TOF), one of complex congenital heart disease.
Methods: The images were post-processed with online QLAB workstation after the 3DE datasets acquired. Cropping functional keys were used to display the volumetric views for the region of interest (ROI) from any angle. Based on Van Praagh sequential segmental approach, TOF was diagnosed in 36 cases aged (2.6±3.9) years old. Two-dimensional echocardiography (2DE) , 3DE and surgical repair were performed within one week.
Results: (1) The examination protocol for 3DE was established. The volumetric views of 3DE were displayed by consecutive orthogonal cropping, including coronal, saggital and horizontal directions. The views of ROI at non-orthogonal planes were also displayed by appropriate cropping. In addition, the typical volumetric views of cardiovascular structures were nominated. (2) TOF was diagnosed with volumetric views by consecutive orthogonal cropping and typical volumetric views of main malformations from 3DE datasets. Compared with surgical exploration, the accordance rate of 3DE in diagnosing TOF was 97.2%. The rate was 97.2% and 94.4% in determining the positions of VSD and RVOTO, respectively, both were higher than 2DE. However, compared with 2DE, 3DE had limitations in detecting co-existed extracardiac anomalies and minute structures (90.6% vs. 71.9%).
Conclusions: Volumetric views of 3DE is a promising imaging modelity in diagnosing TOF with normalized examination protocol, although improvements should be made to better display extracardiac anomalies and minute structures.