The assessment of myocardial motion in gated-SPECT using a multiresolution technique

The assessment of the left ventricular (LV) motion in gated SPECT images is routinely used to identify myocardial ischemia. The precise evaluation of LV motion changes remains a largely qualitative process due to difficulties in quantifying endocardial border position and regional wall motion. In a previous work the authors described a method to estimate motion in image sequences based on the computation of the Optical Flow (OF). A common basic problem in estimating OF concerns how to compute derivative approximations from discrete data. The intrinsic ill-posedness of numerical differentiation can be transformed into a well-posed problem by using filters in the form of scaled convolution operators. Using this approach, the computing of OF can be improved and the information obtained used to measure other physical quantities in a sequence of images. In this work the authors propose and apply to a set of volunteers the measurement of the kinetic energy index, based on OF estimation.