title: Two-dimensional Fourier filtration of acoustic quantification echocardiographic images: improved reproducibility and accuracy of automated measurements of left ventricular performance.
abstract: To determine the accuracy of Fourier filtration in removing the high-frequency component of noise from acoustic quantification (AQ) echocardiographic images, we processed 800 parasternal short-axis images obtained from 10 study subjects. M-mode tracings were also obtained and used 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 diameters (r = 0.91, p < 0.001 for raw AQ; and r = 0.96, p < 0.001, for Fourier filtered images). Fractional shortening showed better correlation between Fourier-filtered images and M-mode (r = 0.79, p < 0.03) versus raw AQ and M-mode (r = 0.33, p = 0.46). Best-to-beat reproducibility was also found to be better for fractional area change (r = 0.82, p = 0.01 versus r = 0.66, p = 0.77), peak area filling rate (r = 0.87, p = 0.004 versus r = 0.62, p = 0.1), and peak are 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 results in more accurate representation of the true endocardial borders.
authors.affiliation: Department of Cardiology, Cleveland Clinic Foundation, Veterans Affairs Medical Center, OH 044195, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chandra
authors.forename: M J
authors.initials: MJ
authors.lastname: Garcia
authors.forename: A
authors.initials: A
authors.lastname: Morehead
authors.forename: J D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D004452:Echocardiography; D015150:Echocardiography, Doppler; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D009200:Myocardial Contraction; D015203:Reproducibility of Results; D016277:Ventricular Function, Left