Validation and application of markerless head motion tracking for a next-generation brain PET scanner

Head motion during brain PET imaging can introduce significant artifacts, reducing image resolution and affecting tracer distribution estimation. To address this issue, real-time head motion tracking and correction have become essential. In this study, we validate the United Imaging Healthcare markerless motion tracking system (UMT) embedded in the next-generation ultra-high performance brain PET scanner, NeuroEXPLORER (NX), using a phantom study and a human FDG study. We apply event-by-event and frame-based motion correction methods to reduce motion blurring and compare the UMT tracking result with the ground truth. Our results show that UMT achieves precise and real-time motion correction for rigid movements, with an error of 0.05 ± 0.04 mm and 0.02 ± 0.02°. The FWHM result demonstrates that employing UMT for motion tracking can improve spatial resolution. Human study results suggest that UMT-based motion correction has the potential to improve clinical applicability by ameliorating PET motion blurring. This study highlights the importance of real-time motion tracking and correction in achieving ideal spatial resolution and improving the clinical value of brain PET imaging. Future studies will focus on real-time motion correction in clinical studies and further evaluation of the UMT-based motion correction in NX.