| 摘要 |
A method of performing Nuclear Magnetic Resonance (NMR) spectroscopy or Magnetic Resonance Imaging (MRI). The methods may include: a) generating a compound comprising a first nuclear species (I1), a second nuclear species (I2), a third nuclear species (S), a heteronuclear coupling asymmetry (|J1S−J2S|) and a nuclear singlet state spin order localized on I1 and I2; b) transferring the nuclear singlet state spin order into heteronuclear magnetization localized on S by applying a single, non-recursive pulse sequence at a low magnetic field in the strong coupling regime of protons; and c) performing NMR spectroscopy or MRI with the compound comprising heteronuclear magnetization localized on S. The |J1S−J2S| may be non-zero. The pulse sequence may include a plurality of sequential radio frequency pulses separated by independent evolution interval. The pulse sequence may be capable of transferring at least about 75% of the nuclear singlet state spin order into heteronuclear magnetization localized on S at any |J1S−J2S| when the independent evolution intervals are optimized. |
