Intermolecular Double-Quantum Coherence Imaging without Coherence Selection Gradients

Yanqin Lin¹, Guiping Sheng¹, Congbo Cai¹, Shuhui Cai¹, Jianhui Zhong², Zhong Chen¹

Intermolecular double-quantum coherences (iDQCs) have some unique properties and have been applied for novel contrast of MRI. In the conventional iDQC imaging experiments, the distant dipolar field (DDF) is generated by coherence selection gradients (CSGs). However, it is found that DDF can arise from certain sample geometry in the absence of CSGs. Here, we demonstrate that sample geometry plays an important role in generating DDF in the absence of CSGs, and this DDF can yield stronger iDQC signal than that from the CSGs if an appropriate phase cycling scheme is adopted. This will facilitate iDQC practical applications.