Premium
Proton diffusion tensor spectroscopy of metabolites in human muscle in vivo
Author(s) -
Brandejsky Vaclav,
Boesch Chris,
Kreis Roland
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25139
Subject(s) - chemistry , nuclear magnetic resonance , diffusion mri , fractional anisotropy , diffusion , anisotropy , nuclear magnetic resonance spectroscopy , metabolite , taurine , spectroscopy , in vivo , analytical chemistry (journal) , proton , magnetic resonance imaging , chromatography , physics , biochemistry , stereochemistry , thermodynamics , medicine , microbiology and biotechnology , amino acid , quantum mechanics , biology , radiology
Purpose To study the apparent diffusivity and its directionality for metabolites of skeletal muscle in humans in vivo by 1 H magnetic resonance spectroscopy. Methods The diffusion tensors were determined on a 3 Tesla MR system using optimized acquisition and processing methods including an adapted STEAM sequence with orientation‐dependent diffusion weighting, pulse‐triggering with individually adapted delays, eddy‐current correction schemes, median filtering, and simultaneous prior‐knowledge fitting of all related spectra. Results The average apparent diffusivities, as well as the fractional anisotropies of taurine (ADC av = 0.74 × 10 −3 s/mm 2 , FA = 0.46), creatine (ADC av = 0.41 × 10 −3 s/mm 2 , FA = 0.33), trimethylammonium compounds (ADC av = 0.48 × 10 −3 s/mm 2 , FA = 0.34), carnosine (ADC av = 0.46 × 10 −3 s/mm 2 , FA = 0.47), and water (ADC av = 1.5 × 10 −3 s/mm 2 , FA = 0.36) were estimated. The diffusivities of most metabolites and water were significantly different from each other. Diffusion was found to be anisotropic and the diffusion tensors showed tensor correlation coefficients close to 1 and were hence found to be essentially coaligned. The magnitudes of apparent metabolite diffusivities were largely ordered according to molecular weight, with taurine as the smallest molecule diffusing fastest, both along and across the fiber direction. Conclusion Diffusivities, directional dependence of diffusion and fractional anisotropies of 1 H MRS‐visible muscle metabolites were presented. It was shown that metabolites share diffusion directionality with water and have similar fractional anisotropies, hinting at similar diffusion barriers. Magn Reson Med 73:481–487, 2015. © 2014 Wiley Periodicals, Inc.