Motion correction of SPEC projection before reconstruction

In Single Photon Emission Computed Tomography (SPECT), the data acquisition occurs over a relatively long time, typically in the range of 5-30 minutes. During this period, the patient must lie still to guarantee the image quality. Nevertheless, patient movement has frequently been reported in clinical applications. This movement causes misalignment of the projection frames, which degrades the reconstructed image and may introduce artifacts. However, the ability to detect and correct for the motion using a computational method is valuable for quality assurance of SPECT imaging. In this work a correlation function based on Linogram and Sinogram of the projection is evaluated in order to estimate the occurred motion and correct it for the best alignment. By our implemented method the motion artifacts of our cases reduced considerably and our results showed that the misalignment (motion) between the projections could be found with a small error depending on the resolution of the images (pixel size), and the time and duration of the applied motion during the course of projection acquisition