Jens T Rosenberg1, Noam Shemesh2, Jose A Muniz1,3, Jean-Nicolas Dumez4, Lucio Frydman1,5, Samuel C Grant1,3. 1. The National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida, USA. 2. Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal. 3. Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida, USA. 4. French National Centre for Scientific Research, Institute de Chime des Substances Naturelles, Gif-sur-Yvette, France. 5. Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel.
Abstract
PURPOSE: This study seeks to evaluate in vivo T2 relaxation times of selectively excited stroke-relevant metabolites via 1 H relaxation-enhanced magnetic resonance spectroscopy (RE-MRS) at 21.1 T (900 MHz). METHODS: A quadrature surface coil was designed and optimized for investigations of rodents at 21.1 T. With voxel localization, a RE-MRS pulse sequence incorporating the excitation of selected metabolites was modified to include a variable echo delay for T2 measurements. A middle cerebral artery occlusion (MCAO) animal model for stroke was examined with spectra taken 24 h post occlusion. Fourteen echo times were acquired, with each measurement completed in less than 2 min. RESULTS: The RE-MRS approach produced high-quality spectra of the selectively excited metabolites in the stroked and contralateral regions. T2 measurements reveal differential results between these regions, with significance achieved for lactic acid. CONCLUSION: Using the RE-MRS technique at ultra-high magnetic field and an optimized quadrature surface coil design, full metabolic T2 quantifications in a localized voxel is now possible in less than 27 min. Magn Reson Med 77:520-528, 2017.
PURPOSE: This study seeks to evaluate in vivo T2 relaxation times of selectively excited stroke-relevant metabolites via 1 H relaxation-enhanced magnetic resonance spectroscopy (RE-MRS) at 21.1 T (900 MHz). METHODS: A quadrature surface coil was designed and optimized for investigations of rodents at 21.1 T. With voxel localization, a RE-MRS pulse sequence incorporating the excitation of selected metabolites was modified to include a variable echo delay for T2 measurements. A middle cerebral artery occlusion (MCAO) animal model for stroke was examined with spectra taken 24 h post occlusion. Fourteen echo times were acquired, with each measurement completed in less than 2 min. RESULTS: The RE-MRS approach produced high-quality spectra of the selectively excited metabolites in the stroked and contralateral regions. T2 measurements reveal differential results between these regions, with significance achieved for lactic acid. CONCLUSION: Using the RE-MRS technique at ultra-high magnetic field and an optimized quadrature surface coil design, full metabolic T2 quantifications in a localized voxel is now possible in less than 27 min. Magn Reson Med 77:520-528, 2017.
Authors: Nastaren Abad; Jens T Rosenberg; Tangi Roussel; Dillon C Grice; Michael G Harrington; Samuel C Grant Journal: Magn Reson Med Date: 2017-09-17 Impact factor: 4.668
Authors: Ghoncheh Amouzandeh; Frederic Mentink-Vigier; Shannon Helsper; F Andrew Bagdasarian; Jens T Rosenberg; Samuel C Grant Journal: Phys Med Biol Date: 2020-02-28 Impact factor: 3.609
Authors: Shannon Helsper; Xuegang Yuan; F Andrew Bagdasarian; Jacob Athey; Yan Li; Cesario V Borlongan; Samuel C Grant Journal: Transl Stroke Res Date: 2022-07-28 Impact factor: 6.800
Authors: Avigdor Leftin; Jens T Rosenberg; Xuegang Yuan; Teng Ma; Samuel C Grant; Lucio Frydman Journal: NMR Biomed Date: 2019-12-03 Impact factor: 4.044