National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005, USA.
Magn Reson Imaging. 2010 Apr;28(3):400-7. doi: 10.1016/j.mri.2009.10.002. Epub 2010 Jan 4.
The first in vivo sodium and proton magnetic resonance (MR) images and localized spectra of rodents were attained using the wide bore (105 mm) high resolution 21.1-T magnet, built and operated at the National High Magnetic Field Laboratory (Tallahassee, FL, USA). Head images of normal mice (C57BL/6J) and Fisher rats (approximately 250 g) were acquired with custom designed radiofrequency probes at frequencies of 237/900 MHz for sodium and proton, respectively. Sodium MR imaging resolutions of approximately 0.125 microl for mouse and rat heads were achieved by using a 3D back-projection pulse sequence. A gain in SNR of approximately 3 for sodium and approximately 2 times for proton were found relative to corresponding MR images acquired at 9.4 T. 3D Fast Low Angle Shot (FLASH) proton mouse images (50x50x50 microm(3)) were acquired in 90 min and corresponding rat images (100x100x100 microm(3)) within a total time of 120 min. Both in vivo large rodent MR imaging and localized spectroscopy at the extremely high field of 21.1 T are feasible and demonstrate improved resolution and sensitivity valuable for structural and functional brain analysis.
利用在国家高磁场实验室（美国佛罗里达州塔拉哈西）建造和运行的宽孔径（105 毫米）高分辨率 21.1-T 磁体，首次获得了啮齿动物的体内钠和质子磁共振（MR）图像和局域谱。使用专门设计的射频探头，在 237/900 MHz 的频率下分别对正常小鼠（C57BL/6J）和费舍尔大鼠（约 250 克）的头部进行成像。通过使用三维后投影脉冲序列，实现了大约 0.125 微米的小鼠和大鼠头部的钠磁共振成像分辨率。与在 9.4 T 处获得的相应磁共振图像相比，钠的 SNR 增益约为 3，质子的 SNR 增益约为 2 倍。在 90 分钟内获得了三维快速低角激发（FLASH）质子小鼠图像（50x50x50 微米），在 120 分钟内获得了相应的大鼠图像（100x100x100 微米）。在 21.1 T 的极高场中进行体内大型啮齿动物磁共振成像和局域光谱学是可行的，并证明了改进的分辨率和灵敏度对于结构和功能脑分析非常有价值。
