Enhanced sensitivity to molecular diffusion with intermolecular double-quantum coherences: implications and potential applications

Apparent molecular self-diffusion rates for 1H intermolecular double-quantum coherences (iDQCs) were measured in solvents covering a wide range of intrinsic diffusion coefficients at 1.5, 9.4 and 14T, and water iDQC diffusion-weighted images were obtained at 1.5T in human brains and at 9.4T in rat brains. Conventional single quantum coherence (SQC) measurements were also made in the same samples. Experimental results indicate that iDQCs are approximately twice as sensitive to diffusion as SQC. A general theoretical expression was derived, and a model was proposed to explain the phenomenon. Potential applications in DWI and brain fMRI were also discussed.