The Quantitative Assessment Of Eccentric Mitral Regurgitation Based On Color Doppler Imaging

Mitral regurgitation is one of the most commonly encountered valve lesions in clinical practice. The quantitative assessment of mitral regurgitation, especially the eccentric regurgitation is important for diagnosis of disease, selection of treatment and timing as well as prognosis evaluation. With its non-invasive character, facility, low-cost and real-time imaging, color Doppler has become significand research modality for assessing mitral regurgitation. However, the common methods for computing regurgitation will tend to underestimate the severity of eccentric regurgitation having specific hemodynamics to great degree. Recently, a certain number research techniques for qualitively and quantitatively or semi-quantitatively assessing mitral regurgitation have been reported, but the accepted golden standard for assessing eccentric mitral regurgitation does not exist. The aim of this thesis is to investigate the quantitative methods for computing regurgitant volume of eccentric mitral regurgitation on the basis of two-dimensional and live three-dimensional colpor Doppler technologies and to realize assessment of the eccentric mitral regurgitation severity accordingly.Firstly, according to the analysis of mapping rule of Color Bars in two-dimensional and three-dimensional color Doppler flow images and Doppler information coding rule, the color information is mapped to flow velocity by building look-up table with regressive analysis and back propogated artificial neural network respectively, and antialiasing flow velocity in turbulent flow exceeding Nyquist limit as corresponding velocity. Secondly, based on the two-dimensional color Doppler technique, stroke regurgitant volume of 42 patients with eccentric regurgitation are calculated by modifying Automated Cardiac Output Measurement method, that is, by spatially and temporally integrating flow velocities through regurgitant valve during...