3D high‐resolution imaging of 2‐hydroxyglutarate in glioma patients using DRAG‐EPSI at 3T in vivo

Abstract

Purpose To develop 3D high‐resolution imaging of 2‐hydroxyglutarate (2HG) at 3T in vivo. Methods Echo‐planar spectroscopic imaging with dual‐readout alternated‐gradients (DRAG‐EPSI), which was recently reported for 2D imaging of 2HG at 7T, was tested for 3D imaging of 2HG at 3T. The frequency drifts and acoustic noise induced by DRAG‐EPSI were investigated in comparison with conventional EPSI. Four patients with IDH‐mutant gliomas were enrolled for 3D imaging of 2HG and other metabolites. A previously reported 2HG‐tailored TE 97‐ms PRESS sequence preceded the DRAG‐EPSI readout gradients. Unsuppressed water, acquired with EPSI, was used as reference for multi‐channel combination, eddy‐current compensation, and metabolite quantification. Spectral fitting was conducted with the LCModel using in‐house basis sets. Results With gradient strength of 4 mT/m and slew rate of 20 mT/m/ms, DRAG‐EPSI produced frequency drifts smaller by 5.5‐fold and acoustic noise lower by 25 dB compared to conventional EPSI. In a 19‐min scan, 3D DRAG‐EPSI provided images of 2HG with precision (CRLB <10%) at a resolution of 10 × 10 × 10 mm3 for a field of view of 240 × 180 × 80 mm3. 2HG was estimated to be 5 mM in a pre‐treatment patient. In 3 post‐surgery patients, 2HG estimates were 3–6 mM, and the 2HG distribution was different from the water‐T2 image pattern or highly concentrated in the post‐contrast enhancing region. Conclusion Together with 2HG‐optimized PRESS, DRAG‐EPSI provides an effective tool for reliable 3D high‐resolution imaging of 2HG at 3T in vivo.

Advanced magnetic resonance spectroscopic neuroimaging: Experts' consensus recommendations

“…Implementation of 2HG measurement for volumetric acquisitions has also been demonstrated (Figure 2). 54,57,58 …”

The diagnostic value of lower glucose consumption for IDH1 mutated gliomas on FDG-PET

“…As for pre-operative molecular diagnosis of gliomas, IDH mutation can be well recognized by identification of 2-HG on 7.0 Tesla magnetic resonance spectroscopy (MRS) [ 10 ]. Other sequences on MR, like dual phase recognition alternating gradient (DRAG)-plane echo spectrum imaging (EPSI), has also been tried to distinguish 2-HG, as 3D imaging on DRAG-EPSI produces a frequency shift 5.5 times smaller and reduce noise by 25 dB compared with conventional method [ 11 ]. It has also been reported that IDH mutation can be predicted by radiomics, or deep learning-based radiomics (DLR) from multiple modalities of MR images by convolutional neural network [ 12 , 13 ].…”

“…Static and dynamic FDG-PET was used to describe IDH1 genotype in gliomas [19,20]. PET images could reveal metabolic differences among gliomas, providing a possible non-invasive preoperative molecular diagnosis with FDG, 11 C-choline(CHO), or 11 C-methionine(MET) [21,22]. MET-PET/MRI has been reported to predict the IDH mutation of gliomas, by calculating the maximum tumor-brain ratio of MET uptake, and the receiver operating characteristic (ROC) analysis showed high AUC of 0.79 [23].…”

2-Hydroxyglutarate in Cancer Cells

“…wt, wild-type. 4 JEŽ EK Phosphoglycerate dehydrogenase. Also, human phosphoglycerate dehydrogenase (PHGDH; EC 1.1.1.95) has been reported to form r-2HG from 2OG (47).…”

“…Typically, millimolar concentrations of 2HG are found in gliomas bearing IDH1/2 mutants ( Table 1 ). In vivo magnetic resonance (MR) imaging using echo-planar spectroscopic imaging dual-readout alternative gradients (DRAG-EPSI) detected 5 m M 2HG before surgery and 3–6 m M after surgery ( 4 ). Similar concentrations were found using long echo time MR spectroscopy with semi-localization by adiabatic selective refocusing.…”