Jandaliyeva Aigerim, Puchnin Viktor, Shchelokova Alena
School of Physics and Engineering, ITMO University, St. Petersburg, Russia.
School of Physics and Engineering, ITMO University, St. Petersburg, Russia.
J Magn Reson. 2024 Feb;359:107627. doi: 10.1016/j.jmr.2024.107627. Epub 2024 Jan 23.
This study comprehensively assesses radiofrequency (RF) volumetric wireless coils utilizing artificial materials for clinical breast MRI. In particular, we evaluated the transmit efficiency, RF safety, and homogeneity of magnetic field amplitude distribution for four structures electromagnetically coupled with a whole-body birdcage coil: extremely high permittivity ceramic coil, solenoid coil, Helmholtz coil, and metamaterial-inspired coil based on periodically coupled split-loop resonators. These coils exhibit favorable attributes, including lightweight construction, compactness, cost-effectiveness, and ease of manufacturing. The results of this study demonstrated that the metamaterial-inspired coil outperforms other wireless coils considered for addressing a specific problem in terms of the set of characteristics. In particular, the metamaterial-inspired coil achieved 85% and 88% homogeneity in magnetic field amplitude distribution at 3 T and 1.5 T MRI, respectively. Also, the 1.5 T metamaterial-inspired coil demonstrated the best performance, increasing the efficiency gain of the birdcage coil by 4.93 times and improving RF safety by 2.96 times. This research explains the limitations and peculiarity of utilizing the volumetric wireless coils in 1.5 and 3 T MRI systems.
本研究全面评估了利用人工材料的射频（RF）容积式无线线圈在临床乳腺磁共振成像中的应用。特别是，我们评估了与全身鸟笼式线圈电磁耦合的四种结构的发射效率、射频安全性和磁场幅度分布的均匀性：极高介电常数陶瓷线圈、螺线管线圈、亥姆霍兹线圈以及基于周期性耦合分裂环谐振器的超材料启发式线圈。这些线圈具有诸多优良特性，包括结构轻巧、紧凑、成本效益高以及易于制造。本研究结果表明，就一系列特性而言，超材料启发式线圈在解决特定问题方面优于其他所考虑的无线线圈。特别是，超材料启发式线圈在3T和1.5T磁共振成像中，磁场幅度分布的均匀性分别达到了85%和88%。此外，1.5T超材料启发式线圈表现出最佳性能，将鸟笼式线圈的效率增益提高了4.93倍，射频安全性提高了2.96倍。本研究阐述了在1.5T和3T磁共振成像系统中使用容积式无线线圈的局限性和特殊性。
