A comparative study of short- and long-TE ¹H MRS at 3 T for in vivo detection of 2-hydroxyglutarate in brain tumors

Abstract

2-Hydroxyglutarate (2HG) is produced in gliomas with mutations of isocitrate dehydrogenase (IDH) 1 and 2. The (1) H resonances of the J-coupled spins of 2HG are extensively overlapped with signals from other metabolites. Here, we report a comparative study at 3 T of the utility of the point-resolved spectroscopy sequence with a standard short TE (35 ms) and a long TE (97 ms), which had been theoretically designed for the detection of the 2HG 2.25-ppm resonance. The performance of the methods is evaluated using data from phantoms, seven healthy volunteers and 22 subjects with IDH-mutated gliomas. The results indicate that TE = 97 ms provides higher detectability of 2HG than TE = 35 ms, and that this improved capability is gained when data are analyzed with basis spectra that include the effects of the volume localizing radiofrequency and gradient pulses.

Keywords: 1H MRS; 2-hydroxyglutarate (2HG); 3 T; IDH-mutated gliomas; human brain; point-resolved spectroscopy (PRESS); short/long TE; volume-localized simulations.