Improvement in motion correction technique for microPET brain imaging

Motion correction (MC) in microPET brain imaging of awake small animals is attracting more interest in preclinical studies to avoid the confounding effects of anesthesia. One of the motion correction methods is to use a stereo optical camera to track the head motion of the animal, which is assumed to be represented by the motion of a tracking marker attached to its forehead. In the presented study, we explored several ways to improve the experimental setup as well as the reconstruction procedures of this method. These approaches include camera distance optimization, improved temporal synchronization of list mode events with motion tracker samples, post-acquisition pose interpolation, and list-mode reconstruction with appropriately selected subsets. These methods were first verified by reconstructing a resolution phantom that underwent continuous motion at different camera distances, and were then applied to a microPET brain scan of an awake rat. The results show that applying the proposed methods leads to a robust experimental setup and motion-corrected reconstructions with improved spatial resolution.