Multimodal imaging issues for electric brain activity mapping in the presence of brain lesions

Abstract

Reconstruction and visualization of sources of EEG activity within the specific patient’s head require the assumption of a precise and realistic volume conductor head model, i.e., a 3-D representation of head’s electrical properties in terms of shape and electrical conductivities. Source reconstruction accuracy is influenced by errors committed in head modeling. Modeling accuracy mainly relies on the correct clinical image-based identification of head structures, characterized by different electrical conductivities, to be included as separate compartments in the model. This paper analyzes the imaging protocols available in clinical practice to define the most suitable procedures for identification of the head structures necessary to build an accurate head model also in the presence of morphologic brain pathologies. Furthermore, tissues anisotropy is discussed and identified as well. With this work we have identified a protocol for the acquisition of multimodal patient’s imaging data for EEG brain activity mapping purposes, able to account for pathological conditions and for head tissues anisotropy.