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

Apparent molecular self-diffusion rates for H-1 intermolecular double-quant um coherences (iDQCs) were measured in solvents covering a wide range of in trinsic diffusion coefficients at 1.5, 9.4 and 14T, and water iDQC diffusio n-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 appr oximately twice as sensitive to diffusion as SQC. A general theoretical exp ression was derived, and a model was proposed to explain the phenomenon. Po tential applications in DWI and brain fMRI were also discussed.