Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
Siemens Healthcare, Knoxville, Tennessee; and.
J Nucl Med. 2020 Oct;61(10):1520-1527. doi: 10.2967/jnumed.119.235770. Epub 2020 Feb 14.
Respiratory gating is the standard to prevent respiration effects from degrading image quality in PET. Data-driven gating (DDG) using signals derived from PET raw data is a promising alternative to gating approaches requiring additional hardware (e.g., pressure-sensitive belt gating [BG]). However, continuous-bed-motion (CBM) scans require dedicated DDG approaches for axially extended PET, compared with DDG for conventional step-and-shoot scans. In this study, a CBM-capable DDG algorithm was investigated in a clinical cohort and compared with BG using optimally gated (OG) and fully motion-corrected (elastic motion correction [EMOCO]) reconstructions. Fifty-six patients with suspected malignancies in the thorax or abdomen underwent whole-body F-FDG CBM PET/CT using DDG and BG. Correlation analyses were performed on both gating signals. Besides static reconstructions, OG and EMOCO reconstructions were used for BG and DDG. The metabolic volume, SUV, and SUV of lesions were compared among the reconstructions. Additionally, the quality of lesion delineation in the different PET reconstructions was independently evaluated by 3 experts. The global correlation coefficient between BG and DDG signals was 0.48 ± 0.11, peaking at 0.89 ± 0.07 when scanning the kidney and liver region. In total, 196 lesions were analyzed. SUV measurements were significantly higher in BG-OG, DDG-OG, BG-EMOCO, and DDG-EMOCO than in static images ( < 0.001; median SUV: static, 14.3 ± 13.4; BG-EMOCO, 19.8 ± 15.7; DDG-EMOCO, 20.5 ± 15.6; BG-OG, 19.6 ± 17.1; and DDG-OG, 18.9 ± 16.6). No significant differences between BG-OG and DDG-OG or between BG-EMOCO and DDG-EMOCO were found. Visual lesion delineation was significantly better in BG-EMOCO and DDG-EMOCO than in static reconstructions ( < 0.001); no significant difference was found when comparing BG and DDG for either EMOCO or OG reconstruction. DDG-based motion compensation of CBM PET acquisitions outperforms static reconstructions, delivering qualities comparable to BG approaches. The new algorithm may be a valuable alternative for CBM PET systems.
呼吸门控是防止 PET 中呼吸效应降低图像质量的标准。使用源自 PET 原始数据的信号进行数据驱动门控 (DDG) 是一种有前途的替代方法，无需使用额外的硬件（例如压力敏感带门控 [BG]）。然而，与传统的步进和拍摄扫描相比，连续床运动 (CBM) 扫描需要为轴向扩展的 PET 开发专用的 DDG 方法。在这项研究中，研究了一种临床队列中使用的 CBM 兼容的 DDG 算法，并使用 BG 比较了最佳门控 (OG) 和完全运动校正 (弹性运动校正 [EMOCO]) 重建。56 例怀疑患有胸部或腹部恶性肿瘤的患者接受了全身 F-FDG CBM PET/CT 检查，使用了 DDG 和 BG。对两种门控信号进行了相关分析。除了静态重建外，还使用 OG 和 EMOCO 重建对 BG 和 DDG 进行了重建。比较了不同重建中的代谢体积、SUV 和病变 SUV。此外，由 3 位专家独立评估了不同 PET 重建中病变勾画的质量。BG 和 DDG 信号之间的全局相关系数为 0.48 ± 0.11，在扫描肾脏和肝脏区域时达到峰值 0.89 ± 0.07。总共分析了 196 个病变。与静态图像相比，BG-OG、DDG-OG、BG-EMOCO 和 DDG-EMOCO 的 SUV 测量值均显著升高（<0.001；中位数 SUV：静态，14.3 ± 13.4；BG-EMOCO，19.8 ± 15.7；DDG-EMOCO，20.5 ± 15.6；BG-OG，19.6 ± 17.1；DDG-OG，18.9 ± 16.6）。BG-OG 和 DDG-OG 之间以及 BG-EMOCO 和 DDG-EMOCO 之间没有发现显著差异。与静态重建相比，BG-EMOCO 和 DDG-EMOCO 中的病变勾画明显更好（<0.001）；在比较 EMOCO 或 OG 重建时，BG 和 DDG 之间没有发现显著差异。CBM PET 采集的基于 DDG 的运动补偿优于静态重建，提供了与 BG 方法相当的质量。该新算法可能是 CBM PET 系统的一种有价值的替代方法。
