Correlation of proton MR spectroscopy and diffusion tensor imaging

Proton magnetic resonance spectroscopy (1H-MRS) provides indices of neuronal damage. Diffusion tensor imaging (DTI) relates to water diffusivity and fiber tract orientation. A method to compare 1H-MRS and DTI findings was developed, tested on phantom and applied on normal brain. Point-resolved spectroscopy (TR/TE=1500/135) was used for chemical shift imaging of a supraventricular volume of interest of 8×8×2 cm3 (64 voxels). In DTI, a segmental spin-echo sequence (TR/TE=5500/91) was used and slices were stacked to reproduce the slab used in MRS. atial distributions of choline and N-acetylaspartate (NAA) correlated to mean fractional anisotropy and apparent diffusion coefficient (ADC) for the inner 6×6=36 voxels defined in MRS, most notably NAA and ADC value (r=−.70, P<.00001; correlation across four subjects, 144 data pairs). This is the first association of neuron metabolite contents in volunteers with structure as indicated by DTI.