Quantitation of intermolecular dipolar effects in NMR spectroscopy and high order MSE MR imaging.
Quantitation of intermolecular dipolar effects in NMR spectroscopy and high order MSE MR imaging.
复制标题
NMR 光谱和高阶 MSE MR 成像中分子间偶极效应的定量。
DOI：
10.1007/bf02678475
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Zhong,J
中科院分区：
文献类型：
--
作者：
Chen,Z;Kennedy,SD;Zhong,J
An analytical expression for intermolecular dipolar effects was derived for the CRAZED sequence with an arbitrary flip angle of the second RF pulse and time-varying gradients. A combination of the demagnetizing field theory and product operator formalism was utilized in the derivation. It is demonstrated that the time-averaged, not instantaneous, orientation of the applied gradients determines the contributions of long-range intermolecular dipole effects. An imaging sequence to detect intermolecular dipolar effects was designed. The second- and third-order multiple spin echo (MSE) NMR signals of swine muscle were observed and were found to be in good agreement with the theoretical predictions. MSE images of a water phantom withnth orders (n=−2, −3, −4, and − 5) were also obtained, and their relative signal intensities and optimized TE values were elucidated and compared with the theoretical prediction.
