NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montréal, Montréal, Quebéc, Canada.
Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, Ontario, Canada.
NMR Biomed. 2023 Nov;36(11):e5002. doi: 10.1002/nbm.5002. Epub 2023 Jul 13.
The quality of cervical spinal cord images can be improved by the use of tailored radiofrequency (RF) coil solutions for ultrahigh field imaging; however, very few commercial and research 7-T RF coils currently exist for the spinal cord, and in particular, those with parallel transmission (pTx) capabilities. This work presents the design, testing, and validation of a pTx/Rx coil for the human neck and cervical/upper thoracic spinal cord. The pTx portion is composed of eight dipoles to ensure high homogeneity over this large region of the spinal cord. The Rx portion is made up of twenty semiadaptable overlapping loops to produce high signal-to-noise ratio (SNR) across the patient population. The coil housing is designed to facilitate patient positioning and comfort, while also being tight fitting to ensure high sensitivity. We demonstrate RF shimming capabilities to optimize B uniformity, power efficiency, and/or specific absorption rate efficiency. B homogeneity, SNR, and g-factor were evaluated in adult volunteers and demonstrated excellent performance from the occipital lobe down to the T4-T5 level. We compared the proposed coil with two state-of-the-art head and head/neck coils, confirming its superiority in the cervical and upper thoracic regions of the spinal cord. This coil solution therefore provides a convincing platform for producing the high image quality necessary for clinical and research scanning of the upper spinal cord.
通过使用针对超高场成像定制的射频（RF）线圈解决方案，可以提高颈椎脊髓图像的质量；然而，目前只有极少数商业和研究用 7-T RF 线圈用于脊髓，特别是那些具有并行传输（pTx）功能的线圈。本工作介绍了一种用于人体颈部和颈椎/上胸段脊髓的 pTx/Rx 线圈的设计、测试和验证。pTx 部分由八个偶极子组成，以确保在脊髓的这个大区域内具有高均匀性。Rx 部分由二十个半适应性重叠环组成，以在患者群体中产生高信噪比（SNR）。线圈外壳的设计便于患者定位和舒适，同时也紧密贴合以确保高灵敏度。我们展示了 RF 匀场能力，以优化 B 均匀性、功率效率和/或比吸收率效率。在成年志愿者中评估了 B 均匀性、SNR 和 g 因子，并在枕叶到 T4-T5 水平证明了出色的性能。我们将提出的线圈与两个最先进的头部和头/颈线圈进行了比较，证实了它在脊髓的颈椎和上胸段的优越性。因此，该线圈解决方案为产生高质量的图像提供了一个令人信服的平台，这些图像是临床和研究扫描上脊髓所必需的。
