Revisiting Concepts of Magnetic Resonance Spectroscopy in the Evaluation of Brain Lesions: An Institutional Experience

Objective Magnetic resonance spectroscopy (MRS) has emerged as a technique due to its ability to characterize the metabolite constituent of any lesion. We have evaluated magnetic resonance (MR) spectral patterns in different neoplastic brain lesions, using the ability of MRS in grading of gliomas. MRS also helps in differentiating between high-grade glioma and metastases. Method A retrospective observational study in histologically confirmed cases of brain neoplasms in which MRS was performed as a part of preoperative MR imaging. The pattern of metabolite peak was observed and means with standard deviation of different metabolite ratios (choline/creatine, choline/N-acetylaspartate [NAA], NAA/creatine) were calculated for different tumors. Analysis was done to see statistically significant differences in metabolite ratios of different grades of gliomas and to differentiate high-grade gliomas from metastases. Result A total of 61 cases with brain tumor were included in the study. Of which, 20 cases were of gliomas, 11 metastases, 9 meningiomas, 4 dysembryoplastic neuroepithelial tumors, 6 pituitary macroadenomas, 4 trigeminal schwannomas, 3 craniopharyngiomas, 2 acoustic schwannomas, and 2 medulloblastomas. Statistically significant differences in ratios of metabolite peaks were noted between different grades of gliomas and for high-grade glioma versus metastases. Conclusion MRS compliments the MR imaging and stands out as problem-solving method to distinguish neoplastic lesions in selected cases and also has a role in grading of gliomas and in differentiation of types of malignancies.