iEEGview: an open-source multifunction GUI-based Matlab toolbox for localization and visualization of human intracranial electrodes

Abstract

Objectives: The precise localization of intracranial electrodes is a fundamental step relevant to the analysis of intracranial electroencephalography (iEEG) recordings in various fields. With the increasing developments of the iEEG studies in human neuroscience, higher requirements have been posed on the localization process, resulting in urgent demands for more integrated, easy-operation and versatile tools for electrodes localization and visualization. Towards addressing this need, we develop an easy-to-use and multifunction toolbox called iEEGview that can be used for the localization and visualization of human intracranial electrodes. Approach: iEEGview is written in Matlab scripts and implemented with a GUI. From the GUI, by taking only pre-implant MRI and post-implant CT images as input, users can directly run the full localization pipeline including brain segmentation, images co-registration, electrodes reconstruction, anatomical information identification, activation map generation and electrodes projection from native brain space into common brain space for group analysis. Additionally, iEEGview implements methods for brain shift correction, visual location inspection on MRI slices and computation of certainty index in anatomical label assignment. Main Results: All the introduced functions of iEEGview work reliably and successfully, which are tested by images from 28 human subjects implanted with depth and/or subdural electrodes. Significance: iEEGview is the first public Matlab GUI based software for intracranial electrode localization and visualization that hold integrated capabilities together within one pipeline. iEEGview promotes convenience and efficiency for the localization process, provides rich localization information for further analysis and offers solutions for addressing raised technical challenges. Therefore, it can serve as a useful tool in facilitating iEEG studies.