脑肿瘤^1H-MRS准确识别并量化Lac和Lip

Accurate Identification and Quantification of Lactate and Lipids by Proton MR Spectroscopy in Brain Tumors

目的:探讨准确地探测、区分并量化大脑质子磁共振波谱检测的乳酸(Lac)和脂质(Lip)代谢物的信息。方法:对28例胶质瘤患者行~1H-MRS检查,用改变TE的方法(TE 144 ms或30 ms)来识别乳酸(Lac)和脂质(Lip),采用洛仑兹函数进行波谱拟合.准确分离并量化Lac和Lip峰。结果:改变TE长短的方法可以准确地区分Lac和Lip峰,洛仑兹线型能较好的拟合MRS波形,拟合结果与原波形的确定系数(R^2)满足0.96≤R^2≤1,有很高的一致性。经独立样本t检验.各级别胶质瘤间Lac值差异均无统计学意义;在Ⅰ～Ⅱ级胶质瘤中均未检测到明显Lip信号,Ⅳ级胶质瘤中Lip含量比Ⅲ级高.两者差异有极显著性意义(P<0.001)。结论:利用改变TE和洛仑兹函数拟合的方法,可以准确地探测、区分并量化脑部Lac和Lip峰,为脑肿瘤的诊断、分类和分级提供重要信息。

Objective：To detect,differentiate as well as quantify lactate and lipids within brain tumors by proton magnetic resonance spectroscopy （^1H-MRS）. Methods：^1 H-MRS was performed in 28 cases with cerebral glioma, Lactate （Lac） and lipids （Lip） were identified by varying the echo time （TE 144ms or 30ms）,then the model of Lorentzian function was used to accurately separate and quantify the Lac and Lip. Results：The peaks of Lac and Lip could be detected and differentiated by varying the echo time. The MRS patterns could be imitated by model of I.orentzian function. The coefficient of determination （R2） was between 0. 96 and 1, showing high degree of consistency. No significant statistical difference was found for Lac value between different grades of cerebral gliomas （P〉0.05） based on t test with Independent-Samples. Signal of lipids was not detected in patients with grade Ⅰ and grade Ⅱ cerebral gliomas,and the level of lipids expression for grade Ⅳ was significantly higher than that for grade Ⅲ ,showing significant statistical differences （P〈0. 001 ）. Conclusion： With the method of varying the echo time and fitting data by Lorentzian function,the Lac and I.ip peaks of brain could be accurately detected, differentiated and quantified by ^1H-MRS, which provided important information for the diagnosis, classification and grading of cerebral tumors.