ELLIPTIC FOURIER APPROXIMATION WITH APPLICATION TO LEFT-VENTRICULAR CONTOUR ANALYSIS

A computer program for the quantitative analysis of left ventricular w all motion, in standard angiography or echography, was developed based on the center-line model. In order to resolve the uncertainties of th e previous implementations, the elliptic Fourier approximation was tes ted on a large set of left ventricular contour pairs, in various patho logical conditions. Fitting a function to the center-line (in the midd le of end diastolic and end systolic contours) makes it possible to pe rform multiple tasks at the same time, in an analytical way and withou t the need of arbitrary parameters, such as search windows. In doing s o, the flexibility and accuracy of this method was demonstrated, more in general, for filtering, interpolation and differentiation of noisy 2D or 3D data. A comparison with standard B-spline was carried out, fo r both open and closed curves, with sparse or equispaced points. The r esulting approximation errors were twice as high as those of the ellip tic Fourier decomposition, still preserving smooth direction and curva ture. Though already described, this methodology deserves more widespr ead application.