In vivo 1 H MR spectroscopy with J-refocusing.
- Resource Type
- Academic Journal
- Authors
- Deelchand DK; Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.; Walls JD; Department of Chemistry, University of Miami, Coral Gables, Florida, USA.; Marjańska M; Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
- Source
- Publisher: Wiley Country of Publication: United States NLM ID: 8505245 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1522-2594 (Electronic) Linking ISSN: 07403194 NLM ISO Abbreviation: Magn Reson Med Subsets: MEDLINE
- Subject
- Language
- English
Purpose: The goal of this study was to propose a novel localized proton MR spectroscopy (MRS) sequence that reduces signal loss due to J-modulation in the rat brain in vivo.
Methods: Sprague-Dawley rats were studied at 9.4 T. A semi-LASER sequence with evenly distributed echo-time (T E ) was used, and a 90° J-refocusing pulse was inserted at T E /2. Proton spectra were acquired at two T E s (30 and 68 ms), with and without the J-refocused pulse. Data were processed in MATLAB and quantified with LCModel.
Results: The J-refocused spectrum acquired at T E = 30 ms did not show any signal losses due to J-modulation and had comparable spectral pattern to the one acquired with semi-LASER using the minimum achievable T E . Higher signal amplitudes for glutamine, γ-aminobutyric acid and glutathione led to more reliable quantification precision for these metabolites. The refocused signal intensities at T E = 68 ms were also unaffected by J-modulation but were smaller than the signals at T E = 30 ms mainly due to transverse T 2 relaxation of metabolites.
Conclusion: The proposed localized MRS sequence will be beneficial in both animal and human MRS studies when using ultra-short T E is not possible while also providing more reliable quantification precision for J-coupled metabolites.
(© 2021 International Society for Magnetic Resonance in Medicine.)