Utility of 4D reconstruction for low-dose cardiac gated SPECT

By modeling major degrading factors in SPECT imaging along with motion-compensated temporal denoising, 4D reconstruction is demonstrated to significantly improve the quality of reconstructed images in cardiac gated SPECT (GSPECT) at the standard dose level. The utility of 4D reconstruction for radiation dose reduction in GSPECT has not been studied despite increased concern in population based risk due to its ionizing radiation. In this work, we investigate the potential of 4D reconstruction on reducing the imaging dose using Monte Carlo simulation of GSPECT imaging of a realistic human phantom at different dose levels. We use a number of metrics to quantify the quality of reconstructed images. The results demonstrate that 4D reconstruction can achieve better or comparable reconstruction at half dose compared to conventional clinical reconstruction at standard dose.