LV volume quantification via spatiotemporal analysis of real-time 3-D echocardiography

This paper presents a method of four-dimensional (4-D) (3-D + Time) space-f requency analysis for directional denoising and enhancement of real-time th ree-dimensional (RT3D) ultrasound and quantitative measures in diagnostic c ardiac ultrasound. Expansion of echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets, These f unctions offer good localization in time and frequency and decompose a sign al into distinct patterns of oriented harmonics, which are invariant to int ensity and contrast range. Deformable-model segmentation is carried out on denoised data after thresholding of transform coefficients, This process at tenuates speckle noise while preserving cardiac structure location, The sup eriority of 4-D over 3-D analysis for decorrelating additive white noise an d multiplicative speckle noise on a 4-D phantom volume expanding in time is demonstrated, Quantitative validation, computed for contours and volumes, is performed on in vitro balloon phantoms. Clinical applications of this sp aciotemporal analysis tool are reported for six patient cases providing mea sures of left ventricular volumes and ejection fraction.