Abstract 2339: A Novel Semi-automated Algorithm for Analysis of Right Ventricular Volume and Function by Real-time 3-Dimensional Echocardiography in Children
Background: Currently available echocardiographic methods for quantifying right ventricular (RV) volumes and ejection fraction (EF) have limited clinical utility. Real-time 3D echocardiography (RT3DE) using a disk-summation method is feasible and accurate for RV measurement but is cumbersome and limited by the image quality and internal structural landmarks of the RV.
Objective: This study sought to evaluate a newly developed semi-automated algorithm based on RV contour detection for quantifying RV volumes and EF using RT3DE in children.
Methods: A total of 20 consecutive children (mean age 10.6 ± 2.8 years) were prospectively enrolled. Transthoracic RT3DE was performed using an X4 matrix array transducer (Philips Medical Systems). Full-volume 3DE datasets were acquired from apical windows. The images were processed offline using a dedicated software package (Research Arena 1.2.2, TomTec Imaging Systems). After adjustment of the cut planes, sagittal, coronal and 4-chamber views of the RV at end systole and end diastole were used to trace the endocardial borders and contours to mark the RV inflow, trabecular portion, outflow and other landmarks. The end systolic volume (ESV), end diastolic volume (EDV) and EF were calculated semi-automatically using a RV contour finding algorithm. MRI was performed using a 1.5T GE CV/i scanner and a FIESTA sequence (GE Medical Systems). Data were analyzed and measured by an independent observer using short axis slices on an offline workstation.
Results: Of the 20 children studied, 3 were excluded because of poor or incomplete RV images (2 RT3DE and 1 MRI studies). For the remaining 17 children, good correlation and agreement between RT3DE and MRI were found (RVEDV: r = 0.95, mean difference = −16.4 ± 15.9 ml, P 0.05; RVEF: r = 0.84, mean difference = − 1.5 ± 4.4 %, P > 0.05). The intra-observer and inter-observer variabilities ranged from −1.1% to 5.8%.
Conclusion: Measurement of RV volumes and EF by RT3DE using the new semi-automated algorithm is feasible and comparable to MRI derived RV measurements in children. This new RT3DE algorithm may become an important clinical tool for longitudinal assessment of RV size and function in children with congenital heart diseases.