A flexible transceiver array based on transmission line resonators (TLRs) combining the advantages of coil arrays with the possibility of form-fitting targeting cardiac MRI at 7 T is presented. The design contains 12 elements which are fabricated on a flexible substrate with rigid PCBs attached on the center of each element to place the interface components, i.e. transmit/receive (T/R) switch, power splitter, pre-amplifier and capacitive tuning/matching circuitry. The mutual coupling between elements is cancelled using a decoupling ring-based technique. The performance of the developed array is evaluated by 3D electromagnetic simulations, bench tests, and MR measurements using phantoms. Efficient inter-element decoupling is demonstrated in flat configuration on a box-shaped phantom (Sij < −19 dB), and bent on a human torso phantom (Sij < −16 dB). Acceleration factors up to 3 can be employed in bent configuration with reasonable g-factors (<1.7) in an ROI at the position of the heart. The array enables geometrical conformity to bodies within a large range of size and shape and is compatible with parallel imaging and parallel transmission techniques.
Hosseinnezhadian, S., Frass-Kriegl, R., Goluch-Roat, S., Pichler, M., Sieg, J., Vít, M., … Laistler, E. (2018). A flexible 12-channel transceiver array of transmission line resonators for 7 T MRI. Journal of Magnetic Resonance, 296, 47–59. https://doi.org/10.1016/j.jmr.2018.08.013