Sato Ryotaro, Odagiri Hayato, Ikawa Manami, Sasaki Hironobu, Takanami Kentaro, Sato Kazuhiro, Usui Akihito, Saito Haruo
Department of Diagnostic Image Analysis, Tohoku University Graduate School of Medicine (Current address: Department of Radiology, Tokyo University Hospital).
Department of Radiology, Tohoku University Hospital.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2020;76(8):795-801. doi: 10.6009/jjrt.2020_JSRT_76.8.795.
This phantom study aimed to determine the optimal acquisition window size for phase-based respiratory gating in silicon photomultiplier (SiPM)-based fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and its acquisition time in respiratory-gated imaging with the optimal window size.
Images of a moving NEMA IEC Body Phantom Set with hot spheres were acquired. First, the tumor volume and the maximum standardized uptake value (SUV) of images reconstructed using a different window size were evaluated to define the optimal window size. Second, the quality of the images reconstructed using the optimal window size and different acquisition times was evaluated using the detectability score of the 10-mm hot sphere and physical indices.
The volume and the SUV of the 10-mm hot sphere were improved when the window size was narrow, and there were no significant differences among images reconstructed using a window size narrower than 20%. To reconstruct an image using the 20% window size, an acquisition time of 5 min was required to visualize the 10-mm hot sphere.
The optimal window size for phase-based respiratory gating is 20%. Further, an acquisition time of 5 min should be taken for respiratory-gated imaging with the 20% window size on SiPM-based FDG-PET/CT.
本体模研究旨在确定基于硅光电倍增管（SiPM）的氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）中基于相位的呼吸门控的最佳采集窗口大小及其在使用最佳窗口大小进行呼吸门控成像时的采集时间。
采集了带有热球的移动NEMA IEC体模集的图像。首先，评估使用不同窗口大小重建的图像的肿瘤体积和最大标准化摄取值（SUV），以确定最佳窗口大小。其次，使用10毫米热球的可检测性评分和物理指标评估使用最佳窗口大小和不同采集时间重建的图像质量。
当窗口大小变窄时，10毫米热球的体积和SUV得到改善，并且使用窄于20%的窗口大小重建的图像之间没有显著差异。要使用20%的窗口大小重建图像，需要5分钟的采集时间才能可视化10毫米热球。
基于相位的呼吸门控的最佳窗口大小为20%。此外，在基于SiPM的FDG-PET/CT上使用20%的窗口大小进行呼吸门控成像时，应采集5分钟的时间。
