Electrical Properties Tomography Based on B(1) Maps in MRI: Principles, Applications and Challenges

Electrical properties (EPs), including conductivity and permittivity, are closely related to many fundamental properties of tissue and its pathological conditions. Noninvasively measuring the in vivo EPs of tissue can have an important impact on biomedical research and clinical applications. Among approaches developed for EP quantification and imaging, electrical properties tomography (EPT) is a promising technology that reconstructs EPs based on the B(1) field distribution that can be measured in the radiofrequency range using an MRI device. In this article, we review the basic principle of EPT, reconstruction methods, biomedical applications including tumor imaging, and existing challenges. As an important application of EPT, the estimation of specific absorption rate (SAR) and its current development are discussed.