| With the advancement of non-invasive neuroimaging techniques,there are a variety of brain imaging techniques for learning and studying the brain at present.Among them,electroencephalogram(EEG)and functional magnetic resonance(fMRI)have been widely used in psychological research and cognitive neuroscience.They have their advantages and disadvantages in terms of spatial and temporal resolution: EEG has a high temporal resolution and fMRI has a high spatial resolution.Simultaneous EEG-fMRI acquisition can achieve complementary advantages and improve spatial and temporal resolution.The advancement of Simultaneous EEG-fMRI acquisition technology will greatly deepen our understanding of advanced brain functions,and further elucidate the neurological mechanisms of advanced cognitive functions such as human attention,execution,and memory,and explore the origins of neuropsychiatric disorders such as epileptic activity and spread disease mechanisms.However,Simultaneous EEG-fMRI acquisition still faces some technical problems,which limits its further promotion and application.Mainly reflected in the mutual influence and interference of magnetic resonance imaging and EEG data acquisition,as well as the image artifacts caused by head movement and EPI sequence itself,and the Simultaneous coil used for the collection of head coils in order to be compatible with EEG caps and other multi-modal imaging equipment is often very large in size,with fewer channels and a simple layout.As a result,its signal-to-noise ratio is low,and its parallel imaging capability is poor.How to optimize the design of Simultaneously acquired devices,especially magnetic resonance RF receiver coils,and reduce the EEG data artifacts and fMRI image artifacts are the main challenges for Simultaneous acquisition.Its performance is a key bottleneck that directly restricts the simultaneous acquisition and application of EEG-fMRI.Because the design of the existing radio frequency coil mainly meets the requirements of magnetic resonance imaging,the special requirements of EEG-fMRI Simultaneous acquisition(exposing the face,etc.)are seldom considered,and the signal-to-noise ratio is relatively low.In this paper,a multi-channel dedicated RF receiver coil for Simultaneous EEG-fMRI acquisition is designed,which improves the spatial confinement of the head coil in the structure,and does not block the face area.Inaddition,the flexible material is used to make the coil more conformable to the human brain.In the circuit design,the coil unit layout optimized by different decoupling methods is used to improve the signal-to-noise ratio.Finally,the phantom and volunteer comparison experiments with the traditional 8-channel head coil were performed on the3 T magnetic resonance.The comparison results show that in the cerebral cortex,the signal-to-noise ratio of the 32-channel Simultaneous EEG-fMRI dedicated RF receiver coil is 1.5 to 2.1 times that of the 8-channel head coil,and when the same resolution is obtained,33% of the scan time can be saved,and the impact on synchronous EEG data acquisition is basically the same.In the energy comparison of the visual area,the dedicated coil is more than 5 times that of the conventional 8-channel head coil,and the dedicated coil can more easily distinguish different visual stimuli.In order to obtain better experimental results,the phantom and volunteer experiments need further optimization. |
