2-DIMENSIONAL FOURIER-FILTRATION OF ACOUSTIC QUANTIFICATION ECHOCARDIOGRAPHIC IMAGES - IMPROVED REPRODUCIBILITY AND ACCURACY OF AUTOMATED MEASUREMENTS OF LEFT-VENTRICULAR PERFORMANCE

To determine the accuracy of Fourier filtration in removing the high-f requency component of noise from acoustic quantification (AQ) echocard iographic images, we processed 800 parasternal short-axis images obtai ned from 10 study subjects. M-mode tracings were also obtained and use d as gold standard for correlating the results from raw AQ and Fourier -filtered images. Left ventricular short-axis diameters measured from the raw AQ and Fourier-filtered data were compared with the M-mode dia meters (r = 0.91, p < 0.001 for raw AQ; and r = 0.96, p < 0.001, for F ourier filtered images). Fractional shortening showed better correlati on between Fourier-filtered images and M-mode (r = 0.79, p < 0.03) ver sus raw AQ and M-mode (r = 0.33, p = 0.46). Beat-to-beat reproducibili ty was also found to be better for fractional area change (r = 0.82, p = 0.01 versus r = 0.66, p = 0.07), peak area filling rate (r = 0.87, p = 0.004 versus p = 0.62, p = 0.1), and peak area emptying rate (r = 0.99, P < 0.0001 versus r = 0.19, p < 0.7) for Fourier filtered versus raw AQ. Our results indicate that Fourier filtration of AQ data resul ts in more accurate representation of the true endocardial borders.