New method for establishing a 3D subject-specific numerical electromagnetic model using hybrid imaging modalities

Numerical electromagnetic models that can mimic the dielectric properties of human tissues have been widely used for dosimetry-related studies in bio-electromagnetics, particularly for the calculation of electromagnetic field distribution inside the human body, which is subject specific. Reports indicated that considerable electromagnetic field variations may occur inside different human subjects even when existing differences in the geometrical dimensions of these subjects are minimal. Therefore, a subject-specific three-dimensional (3D) electromagnetic model is crucially required to calculate the electromagnetic field distribution accurately. However, the manner in which a precise subject-specific 3D electromagnetic model is established has not been fully explored in the literature yet. In this study, a new method was proposed for the establishment of a subject-specific 3D electromagnetic model using hybrid imaging modalities, with computed tomography (CT) and magnetic resonance (MR) images as sources. The exemplary application was provided by using the established subject-specific model to calculate the local specific absorption rates in MR imaging. Comparison studies indicated that detailed information was obtained using the proposed model.