Automatic quantification of three-dimensional kinetic energy in gated myocardial perfusion single-photon-emission computerized tomography improved by a multiresolution technique

摘要

The visualization of the left ventricle (LV) motion in gated single-photon-emission computerized tomography (SPECT) studies is complicated by the fact that 3-D density images cannot be directly presented using common display devices. A number of techniques, most of them concerned with visualization, have been developed to aid in the classification of the images. However, it has been shown that interpretation of LV images by strictly visual techniques is subject to errors and inconsistencies. For this reason, assistance in diagnosis can be improved only through the development of automatic or semiautomatic methods to analyze and to quantify LV parameters. We propose an automatic method to estimate the myocardial kinetic energy directly from gated SPECT sequences based on the optical flow method refined with a multiresolution technique. Specifically, the method quantifies the LV motion by a series of 3-D velocity vector fields computed for each voxel on the sequence of images. The 3-D velocity vector field obtained is used to estimate the kinetic energy, which may be an indication of the cardiac condition. The proposed procedure was applied to a group of volunteers and the cardiac condition of each subject studied by taking the relation between the maximum and minimum values of kinetic energy observed during the cardiac cycle.