Trabesinger Andreas H, Meier Dieter, Dydak Ulrike, Lamerichs Rolf, Boesiger Peter
Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.
Magn Reson Med. 2005 Jul;54(1):51-8. doi: 10.1002/mrm.20544.
Analytical methods are used to characterize the response of the strongly coupled two-spin system of citrate to point-resolved spectroscopy (PRESS)-based sequences at 3 T. The signal output is analyzed line by line, as well as in the Cartesian product operator basis. Patterns with a periodicity of 80.9 ms are identified. Furthermore, it is shown that at TE = n . 80.9 ms (n in {0,1,2,...}), the spin evolution can be described without direct reference to strong coupling terms. The theoretical results are found to be in good agreement with in vivo experiments. These results can be used to design protocols for prostate MRS and MRSI at 3 T, and give guidelines for optimizing spin-echo-based acquisition schemes for detecting two-spin systems at arbitrary field strengths.
采用分析方法来表征柠檬酸盐的强耦合双自旋系统在3T场强下对基于点分辨光谱法（PRESS）序列的响应。逐行分析信号输出，并在笛卡尔积算符基中进行分析。识别出周期为80.9毫秒的模式。此外，结果表明，在TE = n·80.9毫秒（n ∈ {0,1,2,...}）时，无需直接参考强耦合项即可描述自旋演化。理论结果与体内实验结果高度吻合。这些结果可用于设计3T场强下前列腺磁共振波谱（MRS）和磁共振波谱成像（MRSI）的方案，并为优化基于自旋回波的采集方案提供指导，以便在任意场强下检测双自旋系统。
