Overbeck Nanna, Andersen Thomas Lund, Rodell Anders Bertil, Cabello Jorge, Birge Noah, Schleyer Paul, Conti Maurizio, Korsholm Kirsten, Fischer Barbara Malene, Andersen Flemming Littrup, Lindberg Ulrich
Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, 2100 Copenhagen, Denmark.
Department of Clinical Medicine, Copenhagen University, 2100 Copenhagen, Denmark.
Diagnostics (Basel). 2024 Sep 16;14(18):2055. doi: 10.3390/diagnostics14182055.
The outstanding capabilities of modern Positron Emission Tomography (PET) to highlight small tumor lesions and provide pathological function assessment are at peril from image quality degradation caused by respiratory and cardiac motion. However, the advent of the long axial field-of-view (LAFOV) scanners with increased sensitivity, alongside the precise time-of-flight (TOF) of modern PET systems, enables the acquisition of ultrafast time resolution images, which can be used for estimating and correcting the cyclic motion. 0.25 s so-called [F]FDG PET histo image series were generated in the scope of for detecting respiratory and cardiac frequency estimates applicable for performing device-less data-driven gated image reconstructions. The frequencies of the cardiac and respiratory motion were estimated for 18 patients using Short Time Fourier Transform (STFT) with 20 s and 30 s window segments, respectively. The Fourier analysis provided time points usable as input to the gated reconstruction based on eight equally spaced time gates. The cardiac investigations showed estimates in accordance with the measured pulse oximeter references ( = 0.97) and a mean absolute difference of 0.4 ± 0.3 beats per minute (bpm). The respiratory frequencies were within the expected range of 10-20 respirations per minute (rpm) in 16 out of 18 patients. Using this setup, the analysis of three patients with visible lung tumors showed an increase in tumor SUV and a decrease in tumor volume compared to the non-gated reconstructed image. The method can provide signals that were applicable for gated reconstruction of both cardiac and respiratory motion, providing a potential increased diagnostic accuracy.
现代正电子发射断层扫描（PET）突出小肿瘤病变并提供病理功能评估的卓越能力，正受到呼吸和心脏运动导致的图像质量下降的威胁。然而，具有更高灵敏度的长轴视野（LAFOV）扫描仪的出现，以及现代PET系统精确的飞行时间（TOF），使得能够采集超快速时间分辨率图像，可用于估计和校正周期性运动。在检测适用于执行无设备数据驱动门控图像重建的呼吸和心脏频率估计的范围内，生成了0.25秒的所谓[F]FDG PET组织图像系列。分别使用20秒和30秒窗口段的短时傅里叶变换（STFT），对18名患者的心脏和呼吸运动频率进行了估计。傅里叶分析提供了可作为基于八个等间隔时间门的门控重建输入的时间点。心脏检查显示估计值与测量的脉搏血氧仪参考值一致（ = 0.97），平均绝对差值为每分钟0.4±0.3次心跳（bpm）。18名患者中有16名的呼吸频率在每分钟10 - 20次呼吸（rpm）的预期范围内。使用此设置，对三名有可见肺部肿瘤的患者进行分析，结果显示与非门控重建图像相比，肿瘤SUV增加，肿瘤体积减小。该方法可以提供适用于心脏和呼吸运动门控重建的信号，有可能提高诊断准确性。
