Stark Adam J, Han Caleb J, Eisma Jarrod J, Song Alexander K, Garza Maria E, Mann Leah G, Claassen Daniel O, Donahue Manus J
School of Medicine, Vanderbilt University, Nashville, TN, USA.
Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
Clin EEG Neurosci. 2025 Feb 17:15500594251320294. doi: 10.1177/15500594251320294.
Magnetic resonance imaging (MRI) sequences commonly used in simultaneous electroencephalogram (EEG)-MRI studies include blood oxygenation level-dependent (BOLD) and anatomical T-weighted MRI. Safety and electrode heating profiles for these sequences have been well-characterized. However, recent improvements in EEG design may allow for additional sequences to be performed with similar expectations of heating safety, which would expand the EEG-MRI infrastructure for quantitative physiological studies. We evaluated temperature changes ex vivo and in vivo over a wider range of preparation and readout modules with differing specific absorption rate (SAR). A 32-channel EEG cap was used at 3 T and ex vivo heating was assessed for 2D- and 3D-pseudo-continuous-arterial-spin-labeling, 2D-cine, 2D-phase-contrast, 2D T-Relaxation-Under-Spin-Tagging, 32-direction = 1000 s/mm and = 2000 s/mm 2D-diffusion tensor imaging, multiband-BOLD, 3D-T1 MPRAGE, 3D-FLAIR, and 3D-T2. Temperature was monitored with a fiberoptic probe system and plotted over six different electrodes, the amplifier, and battery pack. In vivo assessments were conducted in three participants with the same system. A further in vivo supplemental cohort (n = 10) was used to further evaluate qualitative self-reported heating. Device integrity was evaluated by the manufacturer following experiments. Peak temperature and maximum temperature increases were 23.0°C and 0.4°C respectively ex vivo, and 37.6°C and 0.7°C respectively in vivo. Temperatures did not approach the safety heating threshold of 40°C (defined as a conservative threshold based on manufacturer recommendations and burn injury data). Participants completed in vivo scans without adverse events. No manufacturer-reported device damage was identified. Overall, the tested scans induced heating below critical limits at the clinical field strength of 3 T.
同时进行脑电图（EEG）-磁共振成像（MRI）研究时常用的磁共振成像（MRI）序列包括血氧水平依赖（BOLD）和解剖T加权MRI。这些序列的安全性和电极加热情况已得到充分表征。然而，EEG设计的最新改进可能允许使用类似的加热安全预期来执行其他序列，这将扩展用于定量生理研究的EEG-MRI基础设施。我们在具有不同比吸收率（SAR）的更广泛的准备和读出模块范围内评估了离体和体内的温度变化。在3T场强下使用32通道EEG帽，并对二维和三维伪连续动脉自旋标记、二维电影成像、二维相位对比、二维自旋标记下的T弛豫、32方向=1000 s/mm和=2000 s/mm的二维扩散张量成像、多波段BOLD、三维T1 MPRAGE、三维FLAIR和三维T2进行离体加热评估。使用光纤探头系统监测温度，并在六个不同电极、放大器和电池组上绘制温度曲线。在三名参与者中使用相同系统进行体内评估。另外一个体内补充队列（n = 10）用于进一步评估定性的自我报告加热情况。实验后由制造商评估设备完整性。离体时峰值温度和最大温度升高分别为23.0°C和0.4°C，体内分别为37.6°C和0.7°C。温度未达到40°C的安全加热阈值（根据制造商建议和烧伤损伤数据定义为保守阈值）。参与者完成体内扫描且无不良事件。未发现制造商报告的设备损坏。总体而言，在3T临床场强下，测试扫描引起的加热低于临界极限。
