论文部分内容阅读
Background: One of the great strengths of magnetic resonance spectroscopy(MRS)is its non-invasive and quantitative nature,making it ideally suited for therapeutic monitoring in brain cancer.Studies have shown that reductions in typically high levels of choline(Cho)after therapy may indicate remission whereas a change or increase would suggest progression.Other metabolite changes could also provide prognostic value.The goal of this study was to evaluate the efficacy of conventional one-dimensional(1D)MRS in monitoring the effects of chemoradiotherapy.Methods: 10 subjects with pathologically confirmed gliomas were recruited and examined on a 3T Siemens Skyra using a 32 channel head coil before and after one month of radiochemotherapy.All of the patients were confirmed with IDH mutate.In addition,three healthy subjects underwent repeated scans in order to determine the reproducibility of this method for longitudinal studies.In this study we utilize one conventional method of characterizing MRS: 1D MRS was required using conventional PRESS(TE=30ms,TR=2 sec,128 averages),voxel size is 30x30x30mm,baseline scan images and voxel locations were used for reference when placing the voxel position in the follow-up study.Manual shimming was also matched between exams.1D MRS was post-processed using LCmodel(Provencher)and both metabolite values and ratios were obtained for Nacetyl aspartate(NAA),creatine(Cr),Cho,glutamate/glutamine(Glx),myo-inosoitol(mI),and Lac.Results: Much greater changes were observed in metabolite levels before and after radiochemotherapy.These changes include significantly reduced(p<0.05)Cho/Cr and Lac/Cr ratios.NAA/Cr and Glx/Cr ratios were not significantly different after therapy using either 1D MRS.Conclusion: Our results demonstrate that 1D-MRS results may provide useful information that can be of diagnostic or prognostic value.Future studies include greater exploration of potential differences in other metabolites,such as 2-hydroxyglutarate,specific to IDH-mutated gliomas,that may provide additional pathophysiological information.