Single photon emission computed tomography: an alternative imaging modality in left ventricular evaluation.

Various diagnostic imaging modalities have been used for quantitative left ventricular (LV) parameters. Because of the suboptimal value of the most widely used technology, two-dimensional (2D) echocardiography, 3D ultrasonographic imaging has improved accuracy for LV volume and function. Single photon emission computed tomography (SPECT) is another diagnostic method where LV volumetric and functional parameters can be accurately provided by gated myocardial perfusion tomographic slices. First pass radionuclide venticulography is another imaging modality which has some practical limitations. Despite lower ejection fraction (EF) values compared with invasive approach, noninvasive techniques are accurate in determination of normal and depressed EF. Noninvasive techniques with 3D approach including gated SPECT are beneficial for not only global but also regional LV evaluation. It has been mentioned that the slight difference between echocardiography and SPECT could be caused by the diverse population studied. The results of diagnostic stress tests support that SPECT is feasible to use in evaluation of LV volume and functional analysis. Magnetic resonance imaging is an expensive modality to use routinely, but it preserves its importance in selected patients for providing precise LV geometric data.