Evaluation of the potential impact of reconstruction method on dyssynchrony parameters derived by phase analysis of gated-SPECT MPI: Comparison of two quantitative software

Introduction: Gated SPECT myocardial perfusion scanning has new capabilities in addition to its main applications such as left ventricular dyssynchrony using phase analysis. Phase analysis has been investigated through various software including Emory Cardiac Toolbox (ECTb) and Quantitative Gated SPECT (QGS). The aim of this study is to evaluate the effect of reconstruction parameters on dyssynchrony indices including phase histogram bandwidth (PHB) and phase standard deviation (PSD) derived from two different software packages. Methods: In this study three groups of patients including 47 patients with normal findings 53 patients with Left bundle branch block (LBBB) and 47 patients with heart failure (HF) (including gated studies with 8 or 16 frames). All studies were analyzed by both ECTb and QGS software and reconstructed by both FBP and OSEM reconstruction methods. Then, the PHB and PSD were compared between these methods in separate patient groups. Results: Comparison of two reconstruction methods in ECTb and QGS software showed no statistical difference for mean PHB and PSD parameters except for PHB in HF patients that analyzed with ECTb and obtained by 8 frame. On the other hand, the comparison of two software (QGS and ECTb) showed significant difference for both PHB and PSD, although, the correlation of two software was acceptable and significant. Conclusion: The present study showed that the method of cardiac scan reconstruction had no significant effect on the ranges of dyssynchrony parameters obtained from phase analysis. However, the type of software used for phase analysis, significantly affect the PHB and PSD.