Effects of List-Mode-Based Intraframe Motion Correction in Dynamic Brain PET Imaging

Motion is unavoidable in dynamic 18F-MK6240 positron emission tomography (PET) imaging, especially in Alzheimer's disease (AD) research requiring long scan duration. To understand how motion correction affects quantitative analysis, we investigated two approaches: intra- and inter- frame motion correction (II-MC), which corrects for both the interframe and intraframe motion, and interframe only motion correction (IO-MC), which only corrects for the interframe motion. These methods were applied to 83 scans from 34 subjects, and we calculated distribution volume ratios (DVRs) using the multilinear reference tissue model with the two parameters (MRTM2) in tau-rich brain regions. Most of the studies yielded similar DVR results for both II-MC and IO-MC. However, in one scan of an AD subject, the inferior temporal region showed 14% higher DVR with II-MC compared to IO-MC. This difference was reasonable given the AD diagnosis, although similar results were not observed in other regions. Although discrepancies between IO-MC and II-MC results were rare, they underscore the importance of incorporating intraframe motion correction for more accurate and dependable PET quantitation, particularly in the context of dynamic imaging. These findings suggest that while the overall impact of intraframe motion correction may be subtle, it can improve the reliability of longitudinal PET data, ultimately enhancing our understanding of tau protein distribution in AD pathology.