Respiratory motion reduction with a dual gating approach in myocardial perfusion SPECT: Effect on left ventricular functional parameters

Respiratory motion (RM) complicates the analysis of myocardial perfusion (MP) single-photon emission computed tomography (SPECT) images. The effects of RM on left ventricular (LV) functional variables have not been thoroughly investigated. Thoracic electrical bioimpedance and electrocardiographic signals were recorded from eighteen patients undergoing the rest phase of a 1-day stress/rest cardiac-gated MP-SPECT examination. The signals and list-mode emission data were retrospectively processed to yield standard cardiac- and dual-gated (respiratory and cardiac gating) image sets applying a novel algorithm. LV volume, MP, shape index (SI), wall motion (WM), wall thickening (WT), and phase analysis parameters were measured with Quantitative Perfusion SPECT/Quantitative Gated SPECT software (Cedars-Sinai Medical Center). Image quality was evaluated by three experienced physicians. Dual gating increased LV volume (77.1 +/- 26.8 vs 79.8 +/- 27.6 mL, P = .006) and decreased SI (0.57 +/- 0.05 vs 0.56 +/- 0.05, P = .036) and global WT (39.0 +/- 11.8% vs 36.9 +/- 9.4%, P = .034) compared to cardiac gating, but did not significantly alter perfusion, WM or phase analysis parameters or image quality (P > .05). RM reduction has an effect on LV volume, shape, and WT parameters. RM exerts no significant effect on phase analysis parameters.