Pösse Stefanie, Büther Florian, Mannweiler Dirk, Hong Inki, Jones Judson, Schäfers Michael, Schäfers Klaus Peter
European Institute for Molecular Imaging, University of Münster, Waldeyerstr. 15, Münster, 48149, Germany.
Department of Nuclear Medicine, University Hospital of Münster, Albert-Schweitzer-Campus 1, Münster, 48149, Germany.
EJNMMI Phys. 2020 Mar 30;7(1):19. doi: 10.1186/s40658-020-0285-4.
Respiratory motion in PET/CT leads to well-known image degrading effects commonly compensated using elastic motion correction approaches. Gate-to-gate motion correction techniques are promising tools for improving clinical PET data but suffer from relatively long reconstruction times. In this study, the performance of a fast elastic motion compensation approach based on motion deblurring (DEB-MC) was evaluated on patient and phantom data and compared to an EM-based fully 3D gate-to-gate motion correction method (G2G-MC) which was considered the gold standard.
Twenty-eight patients were included in this study with suspected or confirmed malignancies in the thorax or abdomen. All patients underwent whole-body [F]FDG PET/CT examinations applying hardware-based respiratory gating. In addition, a dynamic anthropomorphic thorax phantom was studied with PET/CT simulating tumour motion under controlled but realistic conditions. PET signal recovery values were calculated from phantom scans by comparing lesion activities after motion correction to static ground truth data. Differences in standardized uptake values (SUV) and metabolic volume (MV) between both reconstruction methods as well as between motion-corrected (MC) and non motion-corrected (NOMC) results were statistically analyzed using a Wilcoxon signed-rank test.
Phantom data analysis showed high lesion recovery values of 91% (2 cm motion) and 98% (1 cm) for G2G-MC and 83% (2 cm) and 90% (1 cm) for DEB-MC. The statistical analysis of patient data found significant differences between NOMC and MC reconstructions for SUV , SUV , MV, and contrast-to-noise ratio (CNR) for both reconstruction algorithms. Furthermore, both methods showed similar increases of 11-12% in SUV and SUV after MC. The statistical analysis of the MC/NOMC ratio found no significant differences between the methods.
Both motion correction techniques deliver comparable improvements of SUV , SUV , and CNR after MC on clinical and phantom data. The fast elastic motion compensation technique DEB-MC may thereby be a valuable alternative to state-of-the art motion correction techniques.
PET/CT中的呼吸运动会导致众所周知的图像退化效应，通常使用弹性运动校正方法进行补偿。门控间运动校正技术是改善临床PET数据的有前景的工具，但重建时间相对较长。在本研究中，基于运动去模糊的快速弹性运动补偿方法（DEB-MC）的性能在患者和体模数据上进行了评估，并与被视为金标准的基于EM的全3D门控间运动校正方法（G2G-MC）进行了比较。
本研究纳入了28例胸部或腹部疑似或确诊恶性肿瘤的患者。所有患者均接受了基于硬件呼吸门控的全身[F]FDG PET/CT检查。此外，使用PET/CT对动态拟人化胸部体模进行了研究，在可控但现实的条件下模拟肿瘤运动。通过将运动校正后的病变活性与静态真实数据进行比较，从体模扫描中计算PET信号恢复值。使用Wilcoxon符号秩检验对两种重建方法之间以及运动校正（MC）和未运动校正（NOMC）结果之间的标准化摄取值（SUV）和代谢体积（MV）差异进行统计分析。
体模数据分析显示，G2G-MC的病变恢复值较高，2cm运动时为91%，1cm运动时为98%；DEB-MC的病变恢复值分别为83%（2cm）和90%（1cm）。对患者数据的统计分析发现，两种重建算法在NOMC和MC重建之间的SUV、SUV、MV和对比噪声比（CNR）存在显著差异。此外，两种方法在MC后SUV和SUV均显示出相似的11-12%的增加。对MC/NOMC比值的统计分析发现，两种方法之间无显著差异。
两种运动校正技术在MC后对临床和体模数据的SUV、SUV和CNR均有可比的改善。因此，快速弹性运动补偿技术DEB-MC可能是现有运动校正技术的有价值替代方案。
