Multinuclear localized spectroscopy at ultra-high field wholebody MRI

超高场全身 MRI 的多核定域光谱

基本信息

批准号：
13470192
负责人：
MITSUMORI Fumiyuki
金额：
$ 7.55万
依托单位：
National Institute for Environmental Studies
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13470192/
关键词：
ultra-high field MRI multinuclear MRS imaging spectroscopy triple-tuned rf coli TEM型信号検出器

项目摘要

We implemented three channels of transmitter and four channels of receiver to the 4.7T MRI spectrometer To enable triple nuclei measurements for ^1H, ^<31>P and ^<13>C, we constructed triple-tuned rf coils. First, we made a dual loop coil (8cm in diameter) for ^<31>P. Then, a single loop coil (12cm in diameter) was added up. These surface coils were integrated with a ^1H TEM coil for head (inner diameter of 30cm). This integrated probe was carefully tuned for three frequencies at 200.43, 81.14, and 50. 40MHz. Couplings among three frequencies were kept small enough. For the software to enable measurements in triple nuclei, we made a pulse sequence combining a ultra-short-echo time STEAM sequence for ^1H and an ISIS sequence for^<31>P This sequence enables us to measure ^1H and ^<31>P spectra from the same localized area in an interleave manner. For the localized spectroscopy for ^<13>C we added up a feature of ^<13>C editing to H localized spectrum. To attain the editing we added an inversion pulse for ^<13>C nucleus during the TM period of the STEAM sequence in alternative scans. TE for the STEAM was also adjusted to 7.7ms, which corresponds to 1/J_<CH> for sp_3-boded CH spins. With a triple tuned coil and a sequence for interleave measurements for ^1H, ^<31>P, and ^<13>C we tested performances of our method. ^1H, ^1H-detected ^<13>C, and ^<31>P spectra were successfully observed in the localized 2x2x2cm^3 area in the phantom sample containing 50 mM acetate, 50mM glutamate, and 100mM ATP. Then we applied the method to human brains. In the 3x3x3cm^3 area in the occipital lobe of human brain we could measure ^1H and ^<31>P spectra in ten minutes. We named this method as TRINITY after TRIple Nuclei In Triple channel spectroscopY.

我们实现了三个传播器和四个接收器通道到4.7T MRI光谱仪，以实现 ^1H， ^<31> p和 ^<13> C的三个核测量值，我们构建了三键的RF线圈。首先，我们以 ^<31> p制作了双环线圈（直径8厘米）。然后，添加一个单回路线圈（直径为12厘米）。这些表面线圈与 ^1H TEM线圈的头部（内径为30厘米）集成。该集成的探针在200.43、81.14和50。40MHz时仔细调整了三个频率。三个频率之间的耦合保持足够小。为了使软件能够在三个核中进行测量，我们制作了一个脉冲序列，结合了 ^1H的超短回声时间蒸汽序列和 ^<31> p的ISIS序列，该序列使我们能够以交际方式测量来自同一局部区域的 ^1H和 ^<31> p光谱。对于 ^<13> C的局部光谱，我们将 ^<13> c编辑的特征添加到h局部频谱中。为了获得编辑，我们在替代扫描中的蒸汽序列的TM周期内添加了一个反转脉冲，用于 ^<13> c核。蒸汽的TE还调整为7.7ms，对应于SP_3-BODED CH旋转的1/J_ <ch>。使用三重调谐线圈和用于 ^1H， ^<31> p和 ^<13> C的交叉测量的序列，我们测试了我们方法的性能。 ^1H， ^1H进行了 ^<13> C，并且在含有50 mm乙酸盐，50mm谷氨酸和100mm ATP的幻象样品中，在局部的2x2x2cm ^3区域中成功观察到了 ^1H进行了 ^<13> c。然后，我们将该方法应用于人的大脑。在人脑枕叶中的3x3x3cm ^3区域中，我们可以在十分钟内测量 ^1H和 ^<31> P光谱。在三通道光谱学中，我们将此方法命名为三位一体。