Real-time three-dimensional color Doppler echocardiography for characterizing the spatial velocity distribution and quantifying the peak flow rate inthe left ventricular outflow tract

Quantification of flow with pulsed-wave Doppler assumes a "flat" velocity p rofile in the left ventricular outflow tract (LVOT), which observation refu tes. Recent development of real-time, three-dimensional (3-D) color Doppler allows one to obtain an entire cross-sectional velocity distribution of th e LVOT, which is not possible using conventional 2-D echo. In an animal exp eriment, the cross-sectional color Doppler images of the LVOT at peak systo le were derived and digitally transferred to a computer to visualize and qu antify spatial velocity distributions and peak flow rates. Markedly skewed profiles, with higher velocities toward the septum, were consistently obser ved. Reference peak flow rates by electromagnetic flow meter correlated wel l with 3-D peak flow rates (r = 0.94), but with an anticipated underestimat ion. Real-time 3-D color Doppler echocardiography was capable of determinin g cross-sectional velocity distributions and peak flow rates, demonstrating the utility of this new method for better understanding and quantifying bl ood flow phenomena. (E-mail: shiotat@ccf.org) (C) 2001 World Federation for Ultrasound in Medicine & Biology.