TOF Data Non-Rigid Motion Correction

PET acquisition requires prolonged scan times, and during the scan a large magnitude of patient motion can occur. Breathing may result in a significant displacement of organs and consequent blurring of clinically relevant features. Various non-rigid motion corrections that act in the image space were proposed to address this problem. TOF data can be considered to be histo-images. Therefore, non-rigid motion correction can be performed in this quasi image space. The TOF locality property can be used to locally perform motion correction; that is, the approximation of motion as locally rigid on a scale of TOF resolution. In this work we investigate motion correction in the TOF data space, assuming a known motion field. Data correction factors, such as normalization and attenuation, will be combined for motion compensation depending on the combination of data. The benefit of the presented motion correction is that only one data set needs to be used for the final reconstruction. An XCAT phantom is used in computer simulations. Initial results showed that the presented methodology accommodates for changes in non-rigid body movements for a typical pattern of patient motion.