Assessment of left ventricular function and volumes by myocardial perfusion scintigraphy - comparison of two algorithms

Aim: Left ventricular volume and function can be computed from gated SPECT myocardial perfusion imaging using Emory Cardiac Toollbox (ECT) or Gated SP ECT Quantification (GS-Quant). The ch of this study was to compare both pro grams with respect to their practical application, stability and precision on heart-models as well as in clinical use. Methods: The volumes of five ca rdiac models were calculated by ECT and GS-Quant. 48 patients (13 female, 3 5 male) underwent a one day stress-rest protocol and gated SPECT. From thes e 96 gated SPECT images, left ventricular ejection fraction (LVEF), end-dia stolic volume (EDV) and end-systolic volume (ESV) were estimated by ECT and GS-Quant. For 42 patients LVEF was also determined by echocardiography. Re sults: For the cardiac models the computed volumes showed high correlation with the model-volumes as well as high correlation between ECT and GS-Quant (r greater than or equal to 0.99). Both programs underestimated the volume by approximately 20-30% independent of the ventricle-size. Calculating LVE F, EDV and ESV, GS-Quant and ECT correlated well to each other and to the L VEF estimated by echocardiography (r greater than or equal to 0.86). LVEF v alues determined with ECT were about IM higher than values determined with GS-Quant or echocardiography. The incorrect surfaces calculated by the auto matic algorithm of GS-Quant for three examinations could flat be corrected manually. 34 of the ECT studies were optimized by the operator. Conclusion: GS-Quant and ECT are two reliable programs in estimating LVEF Both seem to underestimate the cardiac volume. In practical application GS-Quant was fa ster and easier to use. ECT allows the user to define the contour of the ve ntricle and thus is less susceptible to artifacts.