Brui Ekaterina, Mikhailovskaya Anna, Solomakha Georgiy, Efimtcev Alexander, Andreychenko Anna, Shchelokova Alena
School of Physics and Engineering, ITMO University, St. Petersburg, Russia.
School of Physics and Engineering, ITMO University, St. Petersburg, Russia; School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel.
J Magn Reson. 2022 Jun;339:107209. doi: 10.1016/j.jmr.2022.107209. Epub 2022 Mar 30.
This work performs a detailed assessment of radiofrequency (RF) safety and imaging performance of a volumetric wireless coil based on periodically coupled split-loop resonators (SLRs) for 1.5 T wrist MRI versus a commercially available transceive extremity coil. In particular, we evaluated the transmit efficiency and RF safety for three setups: a whole-body birdcage coil, a transceive extremity birdcage coil, and a volumetric wireless coil inductively coupled to the whole-body birdcage coil. The imaging performance of the two latter setups was studied experimentally for nine subjects. The signal-to-noise ratio (SNR) of the images acquired with several standard pulse sequences for osteoarthritis wrist imaging was assessed. Application of the wireless coil significantly improved the specific absorption rate (SAR) efficiency of the whole-body birdcage coil, with at least 4.3-fold and 7.6-fold improvement of local and global SAR efficiencies, respectively. This setup also outperformed the transceive extremity coil in terms of SNR (up to 1.40-fold gain) with a moderate (11%) reduction of the local SAR efficiency.
本研究对一种基于周期性耦合分裂环谐振器（SLR）的用于1.5T手腕磁共振成像（MRI）的容积式无线线圈与市售的收发一体式肢体线圈进行了射频（RF）安全性和成像性能的详细评估。具体而言，我们评估了三种设置的发射效率和RF安全性：全身鸟笼式线圈、收发一体式肢体鸟笼式线圈以及电感耦合至全身鸟笼式线圈的容积式无线线圈。对后两种设置的成像性能进行了针对九名受试者的实验研究。评估了使用几种用于骨关节炎手腕成像的标准脉冲序列采集的图像的信噪比（SNR）。无线线圈的应用显著提高了全身鸟笼式线圈的比吸收率（SAR）效率，局部和全局SAR效率分别至少提高了4.3倍和7.6倍。该设置在SNR方面（增益高达1.40倍）也优于收发一体式肢体线圈，同时局部SAR效率适度降低了11%。
