The aim of this work consists of modeling the left ventricle of the heart, at stress and rest situation, using the myocardial scintigraphic data obtained in 3D stress/rest images and focuses on the possibility of quantification of differences. 32 cardiac patients completed stress and rest tests by Tc99m tetrofosmin in one-day protocol by a GE-Starcam-4000 gammacamera; Images of myocardium were reconstructed by the GE Volumetrix software in the GE Xeleris processing system. Myocardial perfusion was estimated by all (Short axis, HLA (Horizontal Long Axis) and VLA (Vertical Long Axis)) SPECT slices. For each patient, 2 series of transverse slices by tomographic image reconstruction, were produced, using OSEM iterative algorithm. DICOM data was extracted for each patient and an algorithm that integrates 3D visualization has been used for image processing analysis by MatLabR2012b. The appropriate threshold value was identified by creating intensity isocontours. The myocardium volume was evaluated and reconstructed as 3D image and calculations of the differences between the rest and stress data of the 3D images were made. An index ratio of the Volume of Interest (VOI) was determined. The differences between 3D images at rest and stress situations provide us with visual and quantitative evaluation of myocardial perfusion.