Polymer thick film printed & thin film electrodes for simultaneous EEG & high field MRI

This study explores the use of a novel EEG net, Inknet2, which utilizes high-resistance conductive ink on a polymer thick film, to enable high-quality simultaneous EEG and fMRI imaging. Traditional MR-conditional EEG nets often limit the types of MRI sequences that can be used due to image artifacts and radiofrequency shielding. Inknet2 was designed to address these limitations by reducing interference with magnetic fields, thereby expanding the range of usable MRI modalities during simultaneous EEG-fMRI acquisition.
We employed a multi-step approach to evaluate Inknet2’s performance. Simulations were first used to model the net’s effects on magnetic field homogeneity and image quality. These were followed by phantom scans comparing the image quality of scans using a conventional copper EEG net, the Inknet2, and no net. Subsequently, human imaging studies were conducted on five subjects at 3 Tesla and three at 7 Tesla using both structural and functional MRI sequences, with and without Inknet2, to assess the device's practical impact.
Results across simulations, phantom experiments, and human scans consistently showed that Inknet2 caused significantly fewer image artifacts than conventional copper nets. Moreover, image quality obtained with Inknet2 closely matched that of scans without any EEG net, supporting its compatibility with a broad array of MRI sequences at both standard and ultra-high field strengths. These findings highlight the potential of Inknet2 to facilitate advanced multimodal neuroimaging studies that were previously constrained by hardware limitations.