Abstract 14957: Validation of Echocardiography Color Doppler Velocity Reconstruction Against 4d Flow Mri in Assessment of Right Ventricular Intracardiac Flow

Abstract

Introduction: Intracardiac flow imaging of the right ventricle [RV] may improve the management of congenital heart disease like repaired Tetralogy of Fallot [rTOF] or atrial shunts that cause RV dilation [RVD]. However, this is mostly performed via 4D flow magnetic resonance imaging [MRI], which has limited availability and is resource intensive. We propose the use of conventional echocardiography as a viable alternative to assess RV intracardiac flow. Hypothesis: We hypothesize that a velocity reconstruction algorithm implemented for conventional color Doppler echocardiography can resolve flow quantities with good agreement to 4D flow MRI. Methods: We retrospectively collected echos for children with rTOF/RVD and age-matched controls. Color Doppler echos of the RV were evaluated using an in-house algorithm called Doppler Velocity Reconstruction [DoVeR]. Measurements from 4D flow MRI and DoVeR were post-processed to collect hemodynamics parameters for relative pressure difference , vortex strength , total kinetic energy , and viscous energy loss . Agreement between modalities was performed by cross-correlation and L2-norm difference between indexed chamber-average timeseries measurements. Results: 10 rTOF subjects, 3 RVD, and 7 age-matched controls were identified. There was qualitative agreement in spatial and time series measurements between DoVeR and 4D flow MRI (Figure 1). For timeseries measurements, there was strong correlation (median R > 0.85) with low differences (median L2 < 15%) between DoVer and 4D flow MRI. Conclusions: A color Doppler reconstruction method, DoVeR, can effectively measure hemodyanmics parameters using conventional color Doppler echocardiography, with strong agreement against 4D flow MRI. Figure 1: Left – Flow field overlaid onto pressure reconstruction and pressure difference estimates between DoVeR and 4D flow modalities. Right – Correlation coefficient and difference between modality timeseries measurements.