Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA.
Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, USA.
MAGMA. 2023 Jul;36(3):419-426. doi: 10.1007/s10334-022-01036-0. Epub 2022 Aug 20.
Speech production MRI benefits from lower magnetic fields due to reduced off-resonance effects at air-tissue interfaces and from the use of dedicated receiver coils due to higher SNR and parallel imaging capability. Here we present a custom designed upper airway coil for H imaging at 0.55 Tesla and evaluate its performance in comparison with a vendor-provided prototype 16-channel head/neck coil.
Four adult volunteers were scanned with both custom speech and prototype head-neck coils. We evaluated SNR gains of each of the coils over eleven upper airway volumes-of-interest measured relative to the integrated body coil. We evaluated parallel imaging performance of both coils by computing g-factors for SENSE reconstruction of uniform and variable density Cartesian sampling schemes with R = 2, 3, and 4.
The dedicated coil shows approximately 3.5-fold SNR efficiency compared to the head-neck coil. For R = 2 and 3, both uniform and variable density samplings have g-factor values below 1.1 in the upper airway region. For R = 4, g-factor values are higher for both trajectories.
The dedicated coil configuration allows for a significant SNR gain over the head-neck coil in the articulators. This, along with favorable g values, makes the coil useful in speech production MRI.
由于空气-组织界面的离共振效应降低，以及由于更高的 SNR 和并行成像能力而使用专用接收线圈，语音产生 MRI 受益于较低的磁场。在这里，我们为 0.55T 的 H 成像设计了一个定制的上气道线圈，并将其性能与供应商提供的原型 16 通道头/颈线圈进行了比较。
对四名成年志愿者分别用定制的语音线圈和原型头颈线圈进行了扫描。我们评估了每个线圈相对于集成体线圈测量的 11 个上气道感兴趣区域的 SNR 增益。我们通过计算 R=2、3 和 4 时均匀和可变密度笛卡尔采样方案的 SENSE 重建的 g 因子，评估了两个线圈的并行成像性能。
专用线圈相对于头颈线圈显示出约 3.5 倍的 SNR 效率。对于 R=2 和 3，均匀和可变密度采样在上气道区域的 g 因子值均低于 1.1。对于 R=4，两个轨迹的 g 因子值都较高。
专用线圈的配置允许在发音器中相对于头颈线圈获得显著的 SNR 增益。这一点，加上有利的 g 值，使得该线圈在语音产生 MRI 中很有用。
