School of Physics and Engineering, ITMO University, St. Petersburg, Russia.
Medical Institute named after Berezin Sergey (MIBS), St. Petersburg, Russia.
Magn Reson Med. 2023 Mar;89(3):1251-1264. doi: 10.1002/mrm.29507. Epub 2022 Nov 6.
Development of a novel quadrature inductively driven transceive wireless coil for breast MRI at 1.5 T.
A quadrature wireless coil (HHMM-coil) design has been developed as a combination of two linearly polarized coils: a pair of 'metasolenoid' coils (MM-coil) and a pair of Helmholtz-type coils (HH-coil). The MM-coil consisted of an array of split-loop resonators. The HH-coil design included two electrically connected flat spirals. All the wireless coils were coupled to a whole-body birdcage coil. The HHMM-coil was studied and compared to the linear coils in terms of transmit and SAR efficiencies via numerical simulations. A prototype of HHMM-coil was built and tested on a 1.5 T scanner in a phantom and healthy volunteer. We also proposed an extended design of the HHMM-coil and compared its performance to a dedicated breast array.
Numerical simulations of the HHMM-coil with a female voxel model have shown more than a 2.5-fold increase in transmit efficiency and a 1.7-fold enhancement of SAR efficiency compared to the linearly polarized coils. Phantom and in vivo imaging showed good agreement with the numerical simulations. Moreover, the HHMM-coil provided good image quality, visualizing all areas of interest similar to a multichannel breast array with a 32% reduction in signal-to-noise ratio.
The proposed quadrature HHMM-coil allows the -field to be significantly better focused in the region-of-interest compared to the linearly polarized coils. Thus, the HHMM-coil provides high-quality breast imaging on a 1.5 T scanner using a whole-body birdcage coil for transmit and receive.
开发一种新型的正交感应收发无线线圈，用于 1.5T 乳房 MRI。
设计了一种正交无线线圈（HHMM 线圈），它是由两个线性极化线圈组合而成的：一对“超螺旋”线圈（MM 线圈）和一对亥姆霍兹型线圈（HH 线圈）。MM 线圈由一组分裂环谐振器组成。HH 线圈设计包括两个电连接的扁平螺旋。所有无线线圈都与全身鸟笼线圈耦合。通过数值模拟，研究了 HHMM 线圈，并与线性线圈在发射和 SAR 效率方面进行了比较。制作了 HHMM 线圈的原型，并在 1.5T 扫描仪上在体模和健康志愿者中进行了测试。我们还提出了 HHMM 线圈的扩展设计，并将其性能与专用乳房阵列进行了比较。
对女性体素模型进行 HHMM 线圈的数值模拟表明，与线性极化线圈相比，发射效率提高了 2.5 倍以上，SAR 效率提高了 1.7 倍。体模和体内成像与数值模拟吻合良好。此外，HHMM 线圈提供了良好的图像质量，与具有 32%信噪比降低的多通道乳房阵列相似，可以可视化所有感兴趣区域。
与线性极化线圈相比，所提出的正交 HHMM 线圈可以使 B1 场在感兴趣区域得到显著改善。因此，HHMM 线圈可在 1.5T 扫描仪上使用全身鸟笼线圈进行发射和接收，实现高质量的乳房成像。
