Medical Engineering and Technology Research Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271016, China.
Department of Radiology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430079, China.
Med Biol Eng Comput. 2020 Apr;58(4):831-842. doi: 10.1007/s11517-020-02133-9. Epub 2020 Feb 8.
Blood-oxygen-level-dependent (BOLD) signal has been commonly used in functional magnetic resonance imaging (fMRI) to observe the activity in different areas of the brain or other organs. This signal is difficult to simulate, because its amplitude is nearly 1~3% and it is influenced by multiple factors. This study aimed to design and construct an active BOLD simulation phantom and test its stability and repeatability. The phantom consisted of two perpendicular loops. The BOLD signal was simulated by different stimuli generated by a regular periodic vibration current and transmission loops. Three scanners (Siemens skyra 3.0 T, Siemens verio 3.0 T, and GE signa HD 1.5 T) were used to test the stability and repeatability of the BOLD signal detection of the phantom. The percent signal change (PSC) was calculated for each stimulus. At baseline, the phantom exhibited stability, and the average signal variation was below 1% as revealed by the three scanners. The SNR of ROIs with different sizes were markedly high, being 2326.58 and 2389.24; and the ghosting ratio were 0.39% and 0.38%, and the stimuli detection efficiency for Siemens verio and Siemens skyra was 60% and 75%, respectively. The repeated scans of the same scanner for different stimuli were highly reproducible. In the three scanners, the PSC at the same location varied from nearly 1 to 3%. The areas activated on the phantom revealed by different scanners were comparatively consistent. The phantom designed for fMRI quantitative quality control displays good adaptability to different scanners and is easy to operate. It can reliably collect data by simple data processing. Graphical abstract fMRI phantom testing process.
血氧水平依赖（BOLD）信号已广泛应用于功能磁共振成像（fMRI）中，用于观察大脑或其他器官不同区域的活动。该信号难以模拟，因为其幅度接近 1~3%，并且受到多种因素的影响。本研究旨在设计和构建主动 BOLD 模拟体模，并测试其稳定性和可重复性。该体模由两个垂直的环组成。BOLD 信号通过由规则周期性振动电流和传输环产生的不同刺激来模拟。使用三台扫描仪（西门子 skyra 3.0T、西门子 verio 3.0T 和 GE signa HD 1.5T）测试体模的 BOLD 信号检测稳定性和可重复性。为每个刺激计算了信号变化百分比（PSC）。在基线时，体模表现出稳定性，三个扫描仪的平均信号变化均低于 1%。具有不同大小 ROI 的 SNR 明显较高，分别为 2326.58 和 2389.24；鬼影比分别为 0.39%和 0.38%，西门子 verio 和西门子 skyra 的刺激检测效率分别为 60%和 75%。相同扫描仪对不同刺激的重复扫描具有高度可重复性。在三台扫描仪中，同一位置的 PSC 从近 1 到 3%不等。不同扫描仪显示的体模激活区域比较一致。为 fMRI 定量质量控制设计的体模对不同扫描仪具有良好的适应性，易于操作。通过简单的数据处理即可可靠地收集数据。
