Premium
Detection of 2‐hydroxyglutarate in brain tumors by triple‐refocusing MR spectroscopy at 3T in vivo
Author(s) -
An Zhongxu,
Ganji Sandeep K.,
Tiwari Vivek,
Pinho Marco C.,
Patel Toral,
Barnett Samuel,
Pan Edward,
Mickey Bruce E.,
Maher Elizabeth A.,
Choi Changho
Publication year - 2017
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.26347
Subject(s) - in vivo , glutamine , nuclear magnetic resonance , in vivo magnetic resonance spectroscopy , imaging phantom , chemistry , nuclear magnetic resonance spectroscopy , nuclear medicine , magnetic resonance imaging , medicine , physics , biology , amino acid , biochemistry , radiology , microbiology and biotechnology
Purpose To test the efficacy of triple‐refocusing MR spectroscopy (MRS) for improved detection of 2‐hydroxyglutarate (2HG) in brain tumors at 3T in vivo. Methods The triple‐refocusing sequence parameters were tailored at 3T, with density‐matrix simulations and phantom validation, for enhancing the 2HG 2.25‐ppm signal selectivity with respect to the adjacent resonances of glutamate (Glu), glutamine (Gln), and gamma‐aminobutyric acid (GABA). In vivo MRS data were acquired from 15 glioma patients and analyzed with LCModel using calculated basis spectra. Metabolites were quantified with reference to water. Results A triple‐refocusing sequence (echo time = 137 ms) was obtained for 2HG detection. The 2HG 2.25‐ppm signal was large and narrow while the Glu and Gln signals between 2.2 and 2.3 ppm were minimal. The optimized triple refocusing offered improved separation of 2HG from Glu, Gln and GABA when compared with published MRS methods. 2HG was detected in all 15 patients, the estimated 2HG concentrations ranging from 2.4 to 15.0 mM, with Cramer‐Rao lower bounds of 2%–11%. The 2HG estimates did not show significant correlation with total choline. Conclusion The optimized triple refocusing provides excellent 2HG signal discrimination from adjacent resonances and may confer reliable in vivo measurement of 2HG at relatively low concentrations. Magn Reson Med 78:40–48, 2017. © 2016 International Society for Magnetic Resonance in Medicine