New image contrast mechanisms in intermolecular double-quantum coherence human MR imaging.

We have developed a novel magnetic resonance imaging (MRI) method based on the intermolecular double-quantum coherence (DQC) in humans. Combined quantum mechanical and classical formalisms were used to characterize the signal and to aid in the design of a DQC imaging sequence with conventional or echoplanar acquisitions. Imaging contrast was evaluated in volunteers using a 1.5-T clinical scanner. The results demonstrated that the DQC images have contrasts fundamentally different from the conventional images based on single-quantum coherence (SQC). Both our theoretical analysis and experiments suggest that signals from DQCs have a higher signal-to-noise ratio than those from zero-quantum coherence (ZQC) for human brain imaging. The new contrast in DQC imaging may be useful for the detection of varying microstructures, potentially improving the detection of tumors without the need for contrast agents and providing a higher sensitivity and selectivity to magnetic susceptibility distributions in functional MRI brain studies.