Model-based design of measures for four-dimensional cardiac wall motion analysis.

摘要

Left ventricular motion is of particular interest to cardiologists, as various diseases of the heart are associated with depressed, asynchronous, or completely paradoxical wall movement during the cardiac cycle. In fact, regional left ventricular wall motion, assessed most often by visual inspection or tissue Doppler imaging, is commonly used by cardiologists to estimate the extent of disease and evaluate the effectiveness of treatments like cardiac resynchronization therapy. Still, there is a need for better quantification, as there are several limitations of these methods. The primary goal of this thesis is to develop and validate a fully four-dimensional (3D plus time) finite-element-based framework capable of capturing the important features of left ventricular wall motion which are most likely to best reflect the characteristics of the underlying pathology.Several novel aspects of this approach are worth highlighting. First, the additional temporal information currently available with many cardiac imaging modalities, such as real-time three-dimensional echocardiography and cine magnetic resonance imaging, is utilized, rather than wasted, which aligns the analysis more closely with the visual scoring techniques used by cardiologists. Second, the fully spatiotemporal parameterization incorporates time as a continuous parameter, permitting the development of new wall motion indices which are not obtainable through the traditional analysis of end diastole and end systole alone. Third, the finite element model description provides a flexible and compact representation of the dynamic left ventricle, which facilitates rapid in silico testing of candidate wall motion measures under a wide range of simulated conditions.