Department of Children's Clinical Neurophysiology, Helsinki University Central Hospital, Helsinki, Finland; Department of Neurological Sciences, University of Helsinki, Helsinki, Finland.
Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia.
Clin Neurophysiol. 2014 May;125(5):941-6. doi: 10.1016/j.clinph.2013.09.041. Epub 2013 Nov 16.
We aimed to study EEG electrode temperatures during MRI recordings using a neonatal-size phantom to establish the safety of neonatal EEG-MRI.
We constructed a phantom set-up for co-registration of EEG and MRI measurements with newborn size configurations. The set-up consisted of a spherical glass phantom fitted with a customised MRI-compatible 64-channel EEG cap and EEG amplifier. Temperatures were recorded during and after five different scanning sequences (two T2∗ sensitised BOLD fMRI, one T1-weighted and two T2-weighted spin echo) in five electrode locations using a thermistor that was integrated into the electrode housing. A temperature increase >4°C was defined a priori as the safety limit.
During fMRI and T1 sequences, none of the electrodes showed meaningful temperature changes. Only one MRI sequence (T2 with Max turbo factor 25; SAR 89%) caused temperature increase in one electrode (Fpz; +4.1°C) that slightly exceeded our predefined safety limit, while the conventional T2 sequence was within safety limits (up to +1.7°C).
Co-registration of EEG and fMRI can be considered safe in babies with respect to electrode heating, which is the primary safety concern.
The present findings open up a possibility to commence studies where EEG and MRI/fMRI are co-registered in human babies. Such studies hold significant promise of a better understanding of the early development of brain function and neurovascular coupling.
我们旨在使用新生儿大小的体模研究 MRI 记录过程中的 EEG 电极温度，以确定新生儿 EEG-MRI 的安全性。
我们构建了一个体模设置，用于 EEG 和 MRI 测量的配准，具有新生儿大小的配置。该设置包括一个球形玻璃体模，配备了定制的 MRI 兼容的 64 通道 EEG 帽和 EEG 放大器。使用集成在电极外壳中的热敏电阻在五个电极位置记录了五个不同扫描序列（两个 T2∗敏感 BOLD fMRI、一个 T1 加权和两个 T2 加权自旋回波）期间和之后的温度。预先定义温度升高 >4°C 为安全限制。
在 fMRI 和 T1 序列期间，没有一个电极显示出有意义的温度变化。只有一个 MRI 序列（T2，最大涡轮因子 25；SAR 89%）导致一个电极（Fpz）的温度升高（+4.1°C），略微超过我们预先定义的安全限制，而传统的 T2 序列在安全限制内（最高+1.7°C）。
就电极加热而言，EEG 和 fMRI 的配准可以被认为是安全的，这是主要的安全关注点。
这些发现为在人类婴儿中进行 EEG 和 MRI/fMRI 配准的研究开辟了可能性。这些研究有很大的希望更好地理解大脑功能和神经血管耦合的早期发育。
