The Study Of Using H-MRS In The Diagnosis Of Low-grade Glioma、Encephalitides And Cerebral Infarctions

Objective To explore the value of H-MRS in the differential diagnosis ofencephalitides，cerebral infarctions and low-grade glioma．Methods The Philips3.0T MR system for conventional MR imaging andenhanced scan were performed in66cases (the low-grade glioma20cases,26cases of encephalitides，20cases of cerebral infarction),and the interest areaswere set in lesions and lateral normal area,then performed the single voxelproton spectroscopic imaging. The cases of encephalitides and cerebralinfarction were in acute or subacute phase, and the diagnoses were madeclinically in cases with encephalitides or cerebral infarctions and wereconfirmed surgically and pathologically in cases with low-grade glioma.Theclinical and imaging data were compared retrospective between the three groups,and use Function Tool software to analysis spectral data.The ratio change ofNAA/Cr,NAA/Cho, Cho/Cr、Cho/NAA measured from H-MRS were caculatedin lesions area and lateral normal area respectively,and then statistical analyseswere performed by using the software of SPSS16.0Results1. the ratio of Cho／Cr、NAA/Cho、Cho／NAA、NAA/Cr in the low-grade glioma、encephalitides and cerebral infarctions between the lesionsarea and contralateral have statistical significance (P＜0.05)2.The ratio of Cho／Cr、Cho／NAA、NAA／Cho in the low-gradeglioma changed significantly by comparing with those of encephalitides andcerebral infarctions(P＜0.01),the indicators between encephalitis and cerebralinfarction were no significant(P>0.05)3.The area under the ROC curve of Cho/Cr、Cho/NAA、NAA/Cr、NAA/Cho were0.852、0.915、0.258、0.093respectively, Which the cutoff value ofCho/Cr were2.47,the sensitivity、specificity in the differentiation of low-gradeglioma from nonneoplasm (encephalitides、cerebral infarctions) were93﹪、77.8﹪; and the cutoff value of Cho/NAAwere3.18,the sensitivity、specificity in thedifferentiation of low-grade glioma from nonneoplasm(encephalitides、cerebralinfarctions) were93﹪、88.9﹪.Conclusions1. The ratios of Cho／Cr、Cho／NAA and NAA／Cho are hepful Indifferentiating low-grade astrocytomas from encephalitides and cerebralinfarctions2. There is no value of the ratios mentioned above to differentiateencephalitides from cerebral infarctions.3. The quantitative indicators in H-MRS,such as the ratio of Cho／Cr、Cho／NAA used to identify the neoplasms and nonneoplastic have a certainreference value.