Strategy to overcome the spectral overlap between the 2-hydroxyglutarate and lipid resonances at 2.25 ppm

In proton MRS, the 2.25 ppm resonance of 2-hydroxyglutarate (2HG), which gives the largest signal in many acquisition methods, is overlapped with the lipid resonance at 2.25 ppm, complicating evaluation of 2HG in necrotic tumors with elevated lipids. We propose a novel approach for separation of the 2HG and lipid overlapped signals in spectral fitting. We developed new lipid basis sets and tested on proton MRS (PRESS TE 97ms at 3T) data from 43 glioma patients. LCModel fitting using the new lipid basis sets resulted in complete distinction between IDH mutation and wildtype (accuracy, sensitivity, and specificity all unity).