Respiratory gating for a stationary dedicated cardiac SPECT system

Respiratory motion correction is challenging for conventional SPECT systems due to slow rotational data acquisition that leads to inconsistent temporal data. In this study, we developed respiratory gating techniques for a commercially available stationary cardiac SPECT system with multiple pinhole collimators, which acquire all projections simultaneously and avoid the limitation of slow gantry rotation. Respiratory motion was monitored by a compressive sensor attached to the patient/large animal´s lower chest and/or upper abdomen. Respiratory triggers at each end-inspiration peak or cardiac triggers only during end-expiration phases were sent to the GE 570c SPECT/CT system. Respiratory-gated and end-expiration gated images were generated and evaluated with respect to ungated images visually, and quantitatively using contrast recovery on a physical phantom, a canine study and human studies. The results demonstrated that respiratory gating can effectively improve the image quality and contrast for the stationary myocardial perfusion SPECT imaging.