Diagnostic accuracy of 1H-MRS in detecting the oncometabolite 2-hydroxyglutarate (2HG) in adult-type diffuse gliomas

PURPOSE: To evaluate the diagnostic accuracy of three proton magnetic resonance spectroscopy (1H-MRS) strategies-short echo (TE 30 ms), intermediate echo (TE 97 ms), and MEGA-PRESS-for detecting the oncometabolite 2-hydroxyglutarate (2HG) to non-invasively determine isocitrate dehydrogenase (IDH) mutation status in adult-type diffuse gliomas. METHODS: A cohort of 152 patients with adult-type diffuse gliomas (84 IDH-mutant, 68 IDH-wild-type) underwent preoperative 3T MRI incorporating standard morphological sequences and 1H-MRS acquisitions. Spectra were evaluated to assess the presence of a 2HG peak. Diagnostic performance was analysed independently for each method and collectively for a subgroup of patients receiving all three sequences. RESULTS: The intermediate echo (TE 97 ms) method demonstrated 100% specificity and 51.2% sensitivity, while the short echo (TE 30 ms) sequence achieved 97% specificity and 88.9% sensitivity. The MEGA-PRESS method yielded 86.7% specificity and 72.2% sensitivity but was limited by a high non-diagnostic rate (17.5%) due to artifact susceptibility. When combined, the spectroscopy methods achieved 100% sensitivity, 85.7% specificity, and 93.7% overall accuracy in detecting 2HG. CONCLUSION: Conventional PRESS sequences (TE 30 ms and TE 97 ms) outperform MEGA-PRESS for the routine clinical detection of 2HG due to higher technical reliability. An optimized conventional PRESS protocol offers a robust, highly accurate, and non-invasive preoperative tool for identifying glioma genotypes and predicting tumour phenotypes.