Neuroscience Research Institute, Gachon University, Incheon 21988, Korea.
Department of Radiological Science, Gachon University, Incheon 21936, Korea.
Sensors (Basel). 2022 Jun 3;22(11):4274. doi: 10.3390/s22114274.
The optimized size of a single-channel surface radio frequency (RF) coil for mouse body images in a 9.4 T magnetic resonance imaging (MRI) system was determined via electromagnetic-field analysis of the signal depth according to the size of a single-channel coil. The single-channel surface RF coils used in electromagnetic field simulations were configured to operate in transmission/reception mode at a frequency of 9.4 T-400 MHz. Computational analysis using the finite-difference time-domain method was used to assess the single-channel surface RF coil by comparing single-channel surface RF coils of varying sizes in terms of |B|-, |B|-, |B|- and |E|-field distribution. RF safety for the prevention of burn injuries to small animals was assessed using an analysis of the specific absorption rate. A single-channel surface RF coil with a 20 mm diameter provided optimal B-field distribution and RF safety, thus confirming that single-channel surface RF coils with ≥25 mm diameter could not provide typical B-field distribution. A single-channel surface RF coil with a 20 mm diameter for mouse body imaging at 9.4 T MRI was recommended to preserve the characteristics of single-channel surface RF coils, and ensured that RF signals were applied correctly to the target point within RF safety guidelines.
通过根据单通道线圈尺寸对信号深度进行电磁场分析，确定了用于 9.4T 磁共振成像（MRI）系统中鼠体图像的单通道表面射频（RF）线圈的最佳尺寸。在电磁场模拟中使用的单通道表面 RF 线圈被配置为在 9.4T-400MHz 的频率下以传输/接收模式运行。使用有限差分时域方法进行的计算分析通过比较不同尺寸的单通道表面 RF 线圈在|B|、|B|、|B|-和|E|-场分布方面来评估单通道表面 RF 线圈。通过分析特定吸收率来评估用于防止小动物灼伤的 RF 安全性。直径为 20mm 的单通道表面 RF 线圈提供了最佳的 B 场分布和 RF 安全性，从而证实直径≥25mm 的单通道表面 RF 线圈不能提供典型的 B 场分布。建议在 9.4T MRI 上进行鼠体成像时使用直径为 20mm 的单通道表面 RF 线圈，以保持单通道表面 RF 线圈的特性，并确保 RF 信号在 RF 安全指南内正确施加到目标点。
