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

Area of Science:

• Neuroimaging
• Radiochemistry
• Alzheimer's Disease Research

Background:

• Dynamic [¹⁸F]-MK6240 Positron Emission Tomography (PET) imaging is vital for Alzheimer's disease (AD) research, but motion artifacts can impact quantitative analysis.
• Long scan durations in PET studies, particularly for AD, increase the likelihood and severity of motion-induced errors.
• Accurate quantification of tau protein distribution is essential for understanding AD progression and evaluating therapeutic interventions.

Purpose of the Study:

• To evaluate the impact of different motion correction strategies on quantitative analysis in dynamic [¹⁸F]-MK6240 PET imaging.
• To compare the results of inter-frame and intra-frame motion correction (II-MC) versus inter-frame only motion correction (IO-MC).
• To assess the reliability and accuracy of distribution volume ratio (DVR) measurements with varying motion correction techniques.

Main Methods:

• Application of two motion correction methods: II-MC (inter- and intra-frame) and IO-MC (inter-frame only).
• Analysis of 83 dynamic [¹⁸F]-MK6240 PET scans from 34 subjects, including individuals with Alzheimer's disease.
• Calculation of distribution volume ratios (DVR) using the multilinear reference tissue model with two parameters (MRTM2) in tau-rich brain regions.

Main Results:

• Most scans showed similar DVR results between II-MC and IO-MC, indicating minimal differences in many cases.
• A notable exception was observed in one AD subject, where the inferior temporal region exhibited a 14% higher DVR with II-MC compared to IO-MC.
• Discrepancies, though rare, highlight the potential significance of intra-frame motion correction for specific regions and patient cohorts.

Conclusions:

• While the impact of intra-frame motion correction may be subtle in some dynamic PET scans, it is crucial for enhancing the accuracy and dependability of quantitative PET analysis.
• Incorporating II-MC can improve the reliability of longitudinal PET data, leading to a more precise understanding of tau pathology in Alzheimer's disease.
• These findings emphasize the importance of advanced motion correction techniques for robust and reproducible results in neurodegenerative disease imaging.