Quantitative Assessment of Gliomas by Proton Magnetic Resonance Spectroscopy

Background: Advanced magnetic resonance (MR) techniques provide physiological and metabolic information that complements the anatomical information available from conventional MR imaging. The purpose of this study was to evaluate the clinical usefulness of proton MR spectroscopy ( 1 H-MRS) in preoperative quantitative assessment of intracranial gliomas. Patients and Methods: Eight patients with histologically verified gliomas, comprising 2 cases with glioblastoma multiforme (GBM, grade 4), 5 cases with anaplastic oligodendroglioma (AO, grade 3; high-grade glioma), and 1 case with fibrillary astrocytoma (FA, grade 2; low-grade glioma) were evaluated using the 1 H-MRS protocol following conventional MR imaging, diffusion-weighted imaging (DWI), and perfusion-weighted imaging (PWI) preoperatively. Results: High-grade gliomas tended to demonstrate signal hyperintensity by DWI and higher relative cerebral blood volume (rCBV) by PWI. Increased ratios of choline (Cho) to N-acetylaspartate (NAA) (Cho/NAA) and Cho to creatine (Cr) (Cho/Cr) correlated highly with tumor malignancy. The presence of lactate and lipid was predominately detected in patients with high-grade glioma. Conclusion: The combination of multiple MR parameters, based on DWI, PWI and 1 H-MRS, appears valuable for preoperatively predicting the degree of malignancy in glioma.