Investigation of single photon emission computed tomography acquired on helical trajectories

Abstract

This study compares the quality of single photon emission computed tomography images obtained using step-and-shoot and helical trajectories. Monte Carlo simulations of an extended phantom on both trajectories were performed using a parallel hole collimator. Standard filtered-backprojection was used for reconstruction. Both trajectories collected data for the same amount of time. Corresponding to equivalent useful acquisition times, the background signal-to-noise ratios and sphere to background contrasts were roughly equivalent in both reconstructions. However, the helical trajectory requires 20% less true acquisition time due to the elimination of delay due to detector repositioning. Helical trajectories in SPECT can thus reduce overall acquisition time while having negligible effects on image quality.