Diffusion behavior of cerebral metabolites of congenital portal systemic shunt mice assessed noninvasively by diffusion-weighted H-1 magnetic resonance spectroscopy

Diffusion-weighted H-1-MRS (DW-MRS) allows for noninvasive investigation of the cellular compartmentalization of cerebral metabolites. DW-MRS applied to the congenital portal systemic shunt (PSS) mouse brain may provide specific insight into alterations of cellular restrictions associated with PSS in humans. At 14.1 T, adult male PSS and their age-matched healthy (Ctrl) mice were studied using DW-MRS covering b-values ranging from 0 to 45 ms/mu m(2) to determine the diffusion behavior of abundant metabolites. The remarkable sensitivity and spectral resolution, in combination with very high diffusion weighting, allowed for precise measurement of the diffusion properties of endogenous N-acetyl-aspartate, total creatine, myo-inositol, total choline with extension to glutamine and glutamate in mouse brains, in vivo. Most metabolites had comparable diffusion properties in PSS and Ctrl mice, suggesting that intracellular distribution space for these metabolites was not affected in the model. The slightly different diffusivity of the slow decaying component of taurine (0.015 +/- 0.003 mu m(2)/ms in PSS vs 0.021 +/- 0.002 mu m(2)/ms in Ctrl, P < 0.05) might support a cellular redistribution of taurine in the PSS mouse brain.