A wireless bilateral transceiver coil based on volume decoupled resonators for a clinical MR mammography

Wireless radiofrequency coils offer a valuable low cost solution for various MR applications due to several benefits, such as cable-free connection and compatibility with MR platforms of different vendors. Namely, for the purpose of clinical high-field human breast imaging several wireless transceiver coils are known to the date, those operational principle is based on inductive coupling with a body coil. These coils are commonly consist of a several volume resonators to perform bilateral breast imaging. Due to the electrically close location of volume resonators, strong inductive coupling is observed, resulting in the occurrence of hybrid modes. In principle, MR imaging using one of the hybrid modes is possible provided by the homogeneity of a B₁⁺ distribution. However, the question of influence of volume resonators coupling on wireless coil transmit efficiency and receive sensitivity was not previously studied. By this work, we performed study to understand this issue. The first wireless coil with decoupled resonators is developed, evaluated numerically and experimentally including in vivo study on healthy volunteers. Additionally in vivo images were obtained by a conventional receive array to compare with developed wireless coil. According to the obtained results, transmit efficiency and receive sensitivity of a pair of decoupled Helmholtz resonators of the configuration under study is at least 24% higher than for a pair of the same coupled resonators. In vivo images were also obtained using a six-channel receive array to compare with a developed wireless coil. Comparison with a multi-channel receive array have shown that SNR of the developed wireless coil is 10% lower, while time scanning was increased by 68%.