We propose a framework to achieve high-resolution whole-brain conductivity tensor imaging (CTI) with MRI at low frequencies. Our methodology overcomes the limitations of previous approaches based on B1 mapping techniques, both in terms of spatial resolution and brain coverage. This was attained by combining high-frequency conductivity estimates derived from a water-mapping technique with multi-b-value diffusion tensor imaging data. We obtained conductivity values for grey matter and white matter that are in line with previous studies. Overall, our findings highlight noteworthy within- and between- subject variability of the conductivity values.