795-6 Comparison Between Three-Dimensional Reconstruction and Two-Dimensional Imaging for Evaluating Regurgitant Jets: An In Vitro Study

Abstract

The aim of our study was to investigate the applicability of the 3D reconstruction for evaluating color Doppler regurgitant jet imaging compared to conventional 20 color Doppler flow mapping. Steady flows (20–80 cc/sec) were driven through a rectangular orifice (24 mm 2 , length = 8 × width) using a steady flow pump. The regurgitant jets were imaged using 3 different Nyquist velocities (35, 52 and 78 cm/sec)with an Interspec ultrasound system and analyzed using 3D reconstruction with a Tomtec computer. An oblique “birds eye” view from above the orifice plane gave a side view of the flattened jet. Volumes of 3D regurgitant jets were measured and were compared to the conventional color Doppler 2D maximal jet area. The 3D reconstructions showed characteristically elongated and flaring jet propagation for all flow conditions (Figure). Jet areas sliced parallel to the orifice plane provided the most quantifiable jet propagation pattern. A linear relationship between flow rates and 3D jet volumes was obtained (r = 0.91, P < 0.001) whereas conventional 20 maximal jet areas showed a less well defined relationship with actual flow rates (r = 0.87, p < 0.01). The consistency of the relationship between flow rates and jet area in 3D volume over the various Nyquist units was also better for 3D volumes. Our study suggests that three-dimensional jet volume methods should provide more accurate approaches for quantifying regurgitant jets than the conventional 2D jet area measurement.