Quantitative analysis of left ventricle shape and motion, using a 3D dynamic model: deformable superquadrics

Presents a method for the quantitative analysis of the left ventricle mobility, based on the development of a 3D deformable dynamic model. The model is a superquadric-one with different parametric deformations. The data input for the adjustment of this model is a sequence of volumes of the left ventricle obtained in an echocardiography test. An electromechanical device controlled by the computer is adapted. This allows the acquisition of 60 slices in a rotational 3D symmetry. A specialist cardiologist segments the volumes. An objective function is defined to the adjustment of model parameters. The energy of the error is minimized when the parameters are adjusted using a similar focus to the training of the Back Propagation neural network. The dynamics of the position, orientation, size, torsion and its shape have been recovered from the model. This focus permits the obtaining of results which are clinically useful. If we compare quantitatively the volume of the left ventricle and the volume of the developed superquadrics, as a function of time, a small error around 1% is observed in the volume calculation. Therefore, we can conclude that the deformable superquadric captures the global parameters of the left ventricle.