title: Metabolic properties in stroked rats revealed by relaxation-enhanced magnetic resonance spectroscopy at ultrahigh fields.
abstract: (1)H magnetic resonance spectroscopy (MRS) yields site-specific signatures that directly report metabolic concentrations, biochemistry and kinetics-provided spectral sensitivity and quality are sufficient. Here, an enabling relaxation-enhanced (RE) MRS approach is demonstrated that by combining highly selective spectral excitations with operation at very high magnetic fields, delivers spectra exhibiting signal-to-noise ratios >50:1 in under 6 s for ~5 × 5 × 5 (mm)(3) voxels, with flat baselines and no interference from water. With this spectral quality, MRS was used to interrogate a number of metabolic properties in stroked rat models. Metabolic confinements imposed by randomly oriented micro-architectures were detected and found to change upon ischaemia; intensities of downfield resonances were found to be selectively altered in stroked hemispheres; and longitudinal relaxation time of lactic acid was found to increase by over 50% its control value as early as 3-h post ischaemia, paralleling the onset of cytotoxic oedema. These results demonstrate potential of (1)H MRS at ultrahigh fields.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Noam
authors.initials: N
authors.lastname: Shemesh
authors.affiliation: 1] National High Magnetic Field Laboratory, The Florida State University, Tallahassee, Florida 32310, USA [2] Chemical and Biomedical Engineering, The Florida State University, Tallahassee, Florida 32310, USA.
authors.forename: Jens T
authors.initials: JT
authors.lastname: Rosenberg
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Jean-Nicolas
authors.initials: JN
authors.lastname: Dumez
authors.affiliation: 1] National High Magnetic Field Laboratory, The Florida State University, Tallahassee, Florida 32310, USA [2] Chemical and Biomedical Engineering, The Florida State University, Tallahassee, Florida 32310, USA.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Muniz
authors.affiliation: 1] National High Magnetic Field Laboratory, The Florida State University, Tallahassee, Florida 32310, USA [2] Chemical and Biomedical Engineering, The Florida State University, Tallahassee, Florida 32310, USA.
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Grant
authors.affiliation: 1] Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel [2] National High Magnetic Field Laboratory, The Florida State University, Tallahassee, Florida 32310, USA.
authors.forename: Lucio
authors.initials: L
authors.lastname: Frydman
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D004195:Disease Models, Animal; D007511:Ischemia / Q000503:physiopathology; D019344:Lactic Acid / Q000737:chemistry; D060526:Magnetic Fields; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury; D059629:Signal-To-Noise Ratio; D020521:Stroke / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D019344:Lactic Acid