Clinicopathological examination of glioma by proton magnetic resonance spectroscopy background

Abstract

Automation of proton magnetic resonance spectroscopy (MRS) in recent years has made it possible for MRS measurement to be performed in a shorter time than before, and the number of reports of its usefulness for the assessment of glioma malignancy has been increasing in the past several years. We studied the efficacy of proton MRS when used for glioma and conducted clinicopathological examination of glioma. The subjects were 15 patients who had received a pathological diagnosis of glioma at our hospital (6 cases of glioblastoma, 1 case of anaplastic astrocytoma, 4 cases of low-grade astrocytoma, and 4 cases of radiation necrosis); Siemens Magnetom Vision 1.5T was used for the study. Regions of interest (ROIs) were defined as the areas where abnormal signals were found on magnetic resonance imaging (MRI). Areas of primary peaks, such as choline (Cho),N-acetylaspartate (NAA), and lactate (Lac), were measured, and the ratios to normal brain tissue were examined. This study revealed a tendency of increased malignancy of glioma with a decrease in NAA. Some cases also displayed a decrease in Cho with an increase in malignancy. Assessment of malignancy must not be based on a single ROI alone, but several ROIs should be assessed comprehensively. Measurement was difficult when the tumor volume was small. Because diagnosis of very early glioma by MRS seemed difficult, other adjunctive diagnoses may be necessary. Proton MRS is very useful for diagnosis of glioblastoma.