RESUMO
Objective To evaluate the effect of various iterative reconstruction methods on phase analysis of gated myocardial perfusion imaging (MPI). Methods Thirty consecutive patients scanned by the Philips CardioMD system were recruited into this study. The gated SPECT (GSPECT) data were reconstructed with filtered backprojection (FBP),maximum likelihood expectation maximization (MLEM),three-di-mensional (3D) resolution recovery MLEM (AST),attenuation corrected (AC) MLEM,AC and 3D Monte Carlo scatter corrected (ACSC) MLEM methods. Parameters of left ventricular ( LV ) dyssynchrony ( phase standard deviation and histogram bandwidth) were measured using the software SyncTool. Paired t-test was used to compare the differences of the LV dyssynchrony indices between FBP and MLEM,AC MLEM,ACSC MLEM,AST respectively. Results The phase standard deviations of stress GSPECT MPI for FBP,MLEM,AC MLEM,ACSC MLEM,and AST were 11.6°,10.9°,11.2°,11.6°,11.4° respectively;while the histogram bandwidths were 35.7°,34.3°,35.1°,36.9°,35. 1 ° respectively. The phase standard deviations of rest GSPECT MPI for FBP,MLEM,AC MLEM,ACSC MLEM and AST were 15.2°,14. 5°,15.4° ,15. 4°,14.8° respectively; while the histogram bandwidths were 47.3°,46.4°,46.4° ,47.9°,46.1 ° respectively. No statistical significance was observed between the FBP and various iterative reconstruction methods for both the stress and rest GSPECT MPI study (t:-1. 179 to 1.554,P＞0.05 forall). Conclusion The standard FBP reconstruction method is accurate enough for the measurement of LV dyssynchrony indices using the widely used clinical software SyncTool.