Improved motion correction in SPECT imaging using a non-rigid motion model

Non-rigid body motion is a form of patient motion, which, combined with respiratory motion and rigid body motion, leads to artifacts that can degrade SPECT imaging accuracy. In previous work, we proposed a deformation correction method to correct for non-rigid body motion. This approach was validated using simulation and non-patient volunteer studies. However, it was not validated in the clinic with patients. In this paper, we describe an experiment based on two clinical SPECT acquisitions performed with the same patients. For each patient, we first acquire a motion-free projection set, followed by the second acquisition with body motion. This allows the use of reconstructions of the first to serve as a standard for judging the reconstructions of the second. A comparison is made between the motionless baseline reconstruction and the reconstructions of the acquisitions with motion for no corrections, rigid body motion correction, and non-rigid body correction techniques. The result of this experiment shows that the deformation correction can improve the overall SPECT imaging accuracy.