MR-CTI

Conductivity Tensor Imaging (CTI)

Conductivity Tensor Imaging (CTI), is an emerging MRI-based framework that extends conventional electrical properties tomography by resolving the directional dependence of tissue conductivity. While standard EPT techniques assume isotropic conductivity derived from the Laplacian of the transceive phase, CTI introduces a tensorial formulation that captures anisotropic electrical behavior, particularly relevant in structured tissues such as white matter.

The core principle of CTI lies in integrating high-frequency conductivity information obtained from phase-based EPT with microstructural constraints derived from diffusion MRI. By leveraging models such as the standard model of diffusion, CTI decomposes tissue into intra- and extracellular compartments and estimates their respective conductivity contributions. This enables the reconstruction of a full conductivity tensor, reflecting both magnitude and orientation, analogous to diffusion tensor imaging but grounded in electromagnetic properties rather than molecular diffusion.

CTI offers a direct link between tissue microstructure and its electrical characteristics, providing a physically meaningful biomarker for assessing pathological alterations. In neurological applications, it has the potential to improve the characterization of demyelination, neurodegeneration, and conductivity-mediated neuromodulation effects. The framework also opens new avenues for patient-specific modeling in brain stimulation and radiotherapy planning, where accurate knowledge of anisotropic conductivity is critical.

Overall, CTI represents a significant step toward quantitatively mapping the electrical architecture of biological tissues, bridging MRI physics, bioelectromagnetics, and microstructural imaging into a unified, clinically translatable methodology.