Numerical estimation of the B1 transmit field distortion in a copper EEG trace comparison with the thin-film based resistive trace "NeoNet".

Abstract

This study investigates the effects of EEG traces in B1 transmit field distortion in a 3T MRI. EEG is a non-invasive method to monitor brain activities. Although EEG monitors brain activities with a high temporal resolution, it has trouble localizing the signal source. The EEG-fMRI is the multimodal imaging method, but care is needed to use EEG while in MRI as EEG traces create the signal distortion to the MRI. To tackle this problem, resistive traces are developed using thin-film technology to reduce the signal distortion during MRI. Numerical simulation was used to estimate the amount of B1 transmit field distortion of NeoNet and copper-based EEG nets (CuNet - with and without current limiting resistors) compared with the case without EEG net (NoNet). The reduced B1 transmit field distortion is estimated in the case of NeoNet compared to the CuNets. NeoNet is an MR-compatible high-density EEG net designed for pediatric subjects. The proposed NeoNet traces will facilitate/enable such EEG/fMRI pediatric studies with mitigated artifacts, which in turn will help to move the pediatric EEG/fMRI field forward.Clinical Relevance-This study estimates the benefit of the thin-film based EEG net with reduced B1 transmit artifact for the multimodal study of EEG-fMRI. The results are compared with commercial EEG trace made with copper metal with current limiting resistors. It is reported that about 470,000 children are suffering from Epilepsy. The MR-compatible resistive EEG traces se EEG-fMRI has potential to be a valuable tool to help understand pediatric Epilepsy and move the pediatric EEG-fMRI field forward.