Lange Thomas, Trabesinger Andreas H, Schulte Rolf F, Dydak Ulrike, Boesiger Peter
Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
Magn Reson Med. 2006 Dec;56(6):1220-8. doi: 10.1002/mrm.21082.
Two-dimensional (2D) strong-coupling point-resolved spectroscopy (S-PRESS) is introduced as a novel approach to (1)H MR spectroscopy (MRS) in the prostate. The technique provides full spectral information and allows for an accurate characterization of the citrate (Cit) signal. The method is based on acquiring a series of PRESS spectra with constant total echo time (TE). The indirect dimension is encoded by varying the relative lengths of the first and second TEs (TE(1) + TE(2) = TE). In the resulting 2D spectra, only the signal of strongly coupled spin systems is spread into the second dimension, which leads to more clearly arranged spectra. Furthermore, the spectral parameters of Cit (coupling constant J and chemical shift difference delta of the AB spin system) can be determined with high accuracy in vivo. The sequence is analytically optimized for maximal "strong coupling peaks" of Cit at 3T. 2D S-PRESS spectra are compared with JPRESS spectra in vitro as well as in vivo.
二维（2D）强耦合点分辨光谱法（S-PRESS）被引入作为前列腺中氢质子磁共振波谱（MRS）的一种新方法。该技术提供了完整的光谱信息，并能准确表征柠檬酸盐（Cit）信号。该方法基于采集一系列具有恒定总回波时间（TE）的PRESS光谱。间接维度通过改变第一个和第二个TE的相对长度进行编码（TE(1)+TE(2)=TE）。在所得的二维光谱中，只有强耦合自旋系统的信号扩散到第二维度，这使得光谱排列更清晰。此外，Cit的光谱参数（AB自旋系统的耦合常数J和化学位移差δ）可以在体内高精度测定。该序列经过分析优化，以在3T时获得Cit的最大“强耦合峰”。二维S-PRESS光谱在体外和体内均与JPRESS光谱进行了比较。
