The Study Of The Value Of MRS In The Differential Diagnosis Between Brain Metastases And Malignant Gliomas

Objective:To explore the value of magnetic resonance spectroscopy(MRS)in distinguishing brain glioma and metastatic encephaloma.Methods : A retrospective analysis of total 45 cases with brain glioma or metastatic encephaloma that had been examinated by magnetic resonance spectroscopy(MRS).In the 45 cases, there are brain glioma 25 cases and metastatic encephaloma20 cases. And every case has been confirmed by pathological examination. MRS examination includes parenchyma of the tumor enhancement, areas round the tumor and the corresponding normal tissue on offside, and make the most of avoiding hemorrhage, necrosis and cerebrospinal fluid( CSF). To analysis the datum with software of SIEMENSVerio 3.0T magnetic resonance imaging system and hydrogen spectrum analysis software. To explore the application value and advantages of magnetic resonance spectroscopy(MRS) in differential diagnosis of brain glioma and metastatic encephaloma. With scientific statisitical method to compare the differences between different regions of intrest(ROI)of brain glioma and metastatic encephaloma,and besides, to compare with ROIs of normal brain tissue.Results:By analysising the ROIs(parenchyma of the tumor enhancement, areas round the tumor) of every lesion, and comparing with the normal tissues, all parenchyma of 20 cases metastatic encephalomas showed high choline(CHo)andreducing NAA,4 of that had been detected with peak of LAC. 4 cases of brain glioma without NAA peak, other cases showed NAA peak value reducing. All highgrade glioma cases also with high Cho, 6 cases of them had been detected with peak of LAC.Comparing the relative concentration of metabolites in the parenchyma of the two tumors enhancement, no statistical difference was found(P>0.05). Areas round metastatic encephalomas and normal brain tissues are existing similar spectrums. Peak area ratio of every metabolite that detected,no statistical difference was found with normal brain tissues(t=0.725, P= 0.32). Comparing areas round highgrade gliomas and normal tissues of brain, the former with enlargedment of Cho/Cr(t=2.716, P=0.012). Comparing the spectrums of areas round highgrade gliomas and metastatic encephalomas, showed significant difference in Cho/Cr(t=4.835, P= 0.009). There is a significant differenceinBetween the two tumors in NAA/Cr. While, glioma and metastatic encephaloma comparing with corresponding normal brain tissue on offside,no significant difference was found in Lac/Cr(P>0.05). And in each kind of two tumors, their corresponding normal brain tissue on offside showed similar spectrum,the concentration every main metabolite without significant difference, all P values were greater than 5.Conclusion:In the analysis of magnetic resonance spectroscopy(MRS), the spectrum shape of brain glioma or metastatic encephaloma both have a certain change comparing with normal brain tissues. With the technology of MRS, distinguishing the two tumors can be achieved, and the ratio of Cho/Cr and NAA/Cr in areas round tumor is the main point. While, depending on the parenchyma of the two tumors enhancement is difficult to tell the difference between brain glioma or metastatic encephaloma.