  Objective: Global Maxwell Tomography (GMT) is a recently introduced
volumetric technique for noninvasive estimation of electrical properties (EP)
from magnetic resonance measurements. Previous work evaluated GMT using ideal
radiofrequency (RF) excitations. The aim of this simulation study was to assess
GMT performance with a realistic RF coil. Methods: We designed a
transmit-receive RF coil with $8$ decoupled channels for $7$T head imaging. We
calculated the RF transmit field ($B_1^+$) inside heterogeneous head models for
different RF shimming approaches, and used them as input for GMT to reconstruct
EP for all voxels. Results: Coil tuning/decoupling remained relatively stable
when the coil was loaded with different head models. Mean error in EP
estimation changed from $7.5\%$ to $9.5\%$ and from $4.8\%$ to $7.2\%$ for
relative permittivity and conductivity, respectively, when changing head model
without re-tuning the coil. Results slightly improved when an SVD-based RF
shimming algorithm was applied, in place of excitation with one coil at a time.
Despite errors in EP, RF transmit field ($B_1^+$) and absorbed power could be
predicted with less than $0.5\%$ error over the entire head. GMT could
accurately detect a numerically inserted tumor. Conclusion: This work
demonstrates that GMT can reliably reconstruct EP in realistic simulated
scenarios using a tailored 8-channel RF coil design at $7$T. Future work will
focus on construction of the coil and optimization of GMT's robustness to
noise, to enable in-vivo GMT experiments. Significance: GMT could provide
accurate estimations of tissue EP, which could be used as biomarkers and could
enable patient-specific estimation of RF power deposition, which is an unsolved
problem for ultra-high-field magnetic resonance imaging.
