A Quantitative Study of a New RF-coil for 7 Tesla Small-Animal Imaging

In this work we demonstrate a comparative study of the a new proposed coil based on periodic capacitively-loaded thin wires and a conventional loop coil both optimized for small-animal imaging applications at 7 Tesla. The proposed coil uses hybridized eigenmodes of the flat periodic array comprising a number of thin metal wires, excited by a small non-resonant loop. Tunability of the proposed coil within the desired frequency range is ensured by the structural distributed capacity implemented as a PCB attached to the ends of all the wires. The proposed coil was compared to the conventional loop coil with lumped capacitors by numerical simulations. Quantitative comparison has been done in terms of B
⁺
₁
per square root of accepted power efficiency as well as the loaded Q-factor. Up to 42 % improvement of the transmit efficiency has been demonstrated over the conventional loop coil in a homogeneous phantom.