3．0T1H-MRS 鉴别高级别胶质瘤与单发性脑转移瘤的价值

Value of 3.0T 1 H-MRS in the differential diagnosis of high-grade brain gliomas and solitary metastatic tumors

目的根据肿瘤实质区及瘤周水肿区代谢物的差异,评估磁共振波谱成像对鉴别高级别胶质瘤与单发性颅内转移瘤的价值。方法经手术病理证实的高级别脑胶质瘤23例及单发脑转移瘤15例,术前均行常规MRI及1H-M RS检查。检测肿瘤实质区、瘤周水肿区胆碱(Cho)、肌酸(Cr)、N-乙酰天门冬氨酸(NAA)及脂质(Lip)、乳酸(Lac)的变化,计算Cho/Cr、Cho/NAA及NAA/Cr的比值进行比较。对瘤周Cho/Cr、Cho/NAA、NAA/Cr及肿瘤实质内Cho/Cr的比值进行ROC曲线分析。结果高级别胶质瘤与单发脑转移瘤瘤周水肿区Cho/Cr、Cho/NAA、NAA/Cr及肿瘤实质内Cho/Cr的比值差异有统计学意义(P<0.05)。ROC曲线表明瘤周水肿区Cho/Cr比值为1.33时鉴别高级别脑胶质瘤与脑转移瘤的敏感度、特异度及曲线下面积分别为73.9%、100%、89.3%。而瘤周水肿区Cho/NAA比值为1.25时鉴别高级别脑胶质瘤及脑转移瘤的敏感度、特异性及曲线下面积分别为76.2%、100%、90.7%。结论 M RS波谱分析,特别是对瘤周代谢物比值的测量及ROC曲线分析,能够有效鉴别高级别胶质瘤与脑转移瘤。

Objective To assess the value of MR spectroscopy （MRS）in differentiating solitary brain metastases from high-grade gliomas on the basis of differences in metabolite ratios in the intratumoral and peritumoral region.Methods A total of 23 patients with high-grade gliomas and 15 patients with solitary brain metastases underwent MRI and 1 H-MRS before surgery.A variety of metabolite peaks including Cho,Cr,NAA and Lip/Lac were detected in the per-itumoral areas and the tumoral core.The differences in the metabolite ratios were analyzed statistically.Cutoff values of Cho /Cr,Cho /NAA,and NAA/Cr ratios in the peritumoral edema,as well as Cho /Cr ratios in the tumoral core for distinguishing high-grade gliomas from metastases were determined by receiver operating characteristic （ROC）curve analysis.Results Significant differences were noted in the peritumoral Cho /Cr,Cho /NAA,and NAA/Cr ratios between high-grade gliomas and metastases.ROC analysis demonstrated a cutoff value of 1.33 for peritumoral Cho /Cr＆amp;nbsp;ratio to provide sensitivity,specificity and the area under the curve（AUC）of 73.9%,100%,89.3%,respectively. By using a cutoff value of 1.25 for peritumoral Cho /NAA ratio,the sensitivity was 76.2%,the specificity was 100%, and the AUC was 90.7%.Conclusion MRS can differentiate high-grade gliomas from solitary brain metastases,espe-cially with peritumoral measurements and analysis of ROC curve.