Numerical Simulation of 8-Channel Array for Human Brain Imaging using C-Shaped Dipole Antennas with Improved Coverage

An eight-channel coil array based on antenna elements constructed of two partially overlapped C-shaped dipoles has been proposed for the human brain magnetic resonance imaging (MRI) in the ultra-high field (UHF) of 9.4 T. The array can improve the uniformity of the B
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radiofrequency (RF) magnetic field compared to other state-of-the-art RF coil arrays for 9.4T human brain imaging. Using two coupled dipoles allows controlling the field distribution along the longitudinal direction in the human head and increases coverage of the RF field along the same direction. By numerical simulations, the uniformity, specific absorption rate (SAR), and Tx-efficiency of the RF field were analyzed for various overlap lengths of the active and passive dipole within a single antenna element. The realization of the proposed array showing the best coverage has been obtained and numerically demonstrated. The proposed array is simple and robust compared to other coil designs. It can be used for brain and upper spine imaging applications at ultra-high field strengths.