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.

中文翻译：

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基于活动体模的BOLD信号仿真和fMRI质量控制：初步研究。

功能性磁共振成像（fMRI）中通常使用血氧水平依赖性（BOLD）信号来观察大脑或其他器官不同区域的活动。该信号的幅度接近1〜3％，受多种因素的影响，难以模拟。这项研究旨在设计和构建一个主动的BOLD仿真体模，并测试其稳定性和可重复性。体模由两个垂直环组成。通过定期的周期性振动电流和传输回路产生的不同刺激来模拟BOLD信号。使用三台扫描仪（Siemens skyra 3.0 T，Siemens verio 3.0 T和GE signa HD 1.5 T）测试幻像的BOLD信号检测的稳定性和可重复性。计算每种刺激的信号变化百分比（PSC）。在基线时 幻影显示出稳定性，并且三个扫描仪显示平均信号变化低于1％。不同大小的ROI的SNR显着较高，分别为2326.58和2389.24；重影率分别为0.39％和0.38％，Siemens verio和Siemens skyra的刺激检测效率分别为60％和75％。同一扫描仪针对不同刺激的重复扫描具有很高的再现性。在这三台扫描仪中，同一位置的PSC值从近1％到3％不等。由不同扫描仪显示的幻像上激活的区域相对一致。专为fMRI定量质量控制而设计的体模对不同的扫描仪显示出良好的适应性，并且易于操作。它可以通过简单的数据处理可靠地收集数据。图形化抽象fMRI体模测试过程。