Evaluation of new automated gated-SPECT and echocardiographic methods for calculating left ventricular volumes and...

Left ventricular (LV) volumes and ejection fraction (LVEF) are assessed using ECG-gated myocardial perfusion scintigraphy (MPS) and echocardiography. We have developed CAFU, a new automated method for the quantification of MPS images. AutoEF software is a new automated method for quantifying echocardiograms (Tomtec research arena). The aim of the study was to compare these new methods with standard methods.

Patients undergoing clinical MPS were invited to an echocardiographic examination. Eighty-eight patients were included, mean age 64+/-10 years, 50% men. LV volumes and LVEF from the echocardiographic examinations were calculated using the AutoEF software and calculations according to Simpson's rule. The LV volumes and LVEF from the MPS images were calculated using CAFU, Quantitative gated-SPECT (QGS) and Emory Cardiac Toolbox (ECT).

The MPS methods revealed larger LV volumes and LVEF compared with the echocardiographic methods. CAFU showed an excellent correlation with QGS and ECT (0.91-0.99). The correlations between the MPS and the echocardiographic methods (0.47-0.88), as well as between the AutoEF-assessed values and Simpson's method (0.57-0.87), were lower, however statistically significant. The correlations between the methods were higher for LV volumes than for LVEF.

There was better agreement between LV volumes and LVEF values from the three MPS methods than between those from the two echocardiographic methods. The echocardiographic methods produced significantly lower LV volumes and LVEF compared with the MPS methods. In the clinical situation, LV volumes and LVEF values from different types of examination or different software packages should be treated with caution.