质子磁共振波谱在脑肿瘤中的应用研究

The Clinical Application of 1 HMRS in Brain Tumor

目的 研究脑肿瘤质子磁共振波谱的不同表现及其临床应用价值。材料与方法 搜集行质子磁共振波谱检查并经病理追踪证实的 6 5例脑肿瘤患者 ,其中Ⅰ～Ⅱ级星形细胞瘤 12例 ,Ⅲ级星形细胞瘤 6例 ,成胶质细胞瘤 8例 ,胶质瘤术后复发 4例 ,脑膜瘤 9例 ,转移瘤 17例 ,神经鞘瘤 4例 ,垂体瘤 4例 ,表皮样囊肿 1例 ;对侧正常相应部位作为自身对照组 2 0例。观察定点分辨选择波谱 (PRESS)采集N 乙酰天门冬氨酸 (NAA)、肌酸 /磷酸肌酸 (Cr/PCr)、含胆碱类化合物 (Cho)及乳酸 (Lac)的共振峰 ,化学位移成像(CSI)代谢物的区域分布和回波脉冲序列 (STEAM )对脂质 (Lip)、丙氨酸 (Ala)等短T2 代谢物的显示。结果 同对照组比较脑肿瘤NAA有不同程度下降 (P <0 .0 5 ) ;脑外肿瘤NAA低于脑内肿瘤 ,脑膜瘤NAA/Cr、NAA/Cho比Ⅲ级星形细胞瘤低 (P <0 .0 5 ) ;NAA减少在肿瘤中心明显 ;在肿瘤坏死区及术后残腔几乎测不到NAA。胶质瘤实体部分Cho信号增加 (P <0 .0 0 5 ) ;成胶质细胞瘤Cho/Cr比Ⅰ～Ⅱ级星形细胞瘤高 (P <0 .0 5 ) ;4例肿瘤复发Cho明显升高。约 2 1.5 %的肿瘤显示Lac峰 ,其中高级别胶质瘤坏死区和术后残腔 8例 ,表皮样囊肿 1例 ,神经鞘瘤囊变区 2例 ,肿瘤水肿区 3例。约 2 1%的未经治疗的胶质瘤出现Lip信号 ;

Objective To investigate 1 HMRS findings of brain tumor and the clinical application of 1 HMRS.Materials and Methods Sixty five patients with pathologically proved brain tumor, who had underwent 1 HMRS, were collected. The tumors included Ⅰ～Ⅱ ostrocytoma (n=12), Ⅲ ostrocytoma (n=6), glioblastoma( n=8), recurred glioma (n=4), meningioma (n=9), metastases (n=17), neurinoma (n=4), pituitory tumor (n=4) and epidermoid (n=1). Normal contralateral hemispheres of 20 cases were used as control group. NAA, Cr/PCr. Cho and Lac were observed with PRESS, while the distribution of metabolites with CSI, short T 2 metabolites such as Lip, Ala with STEAM.Results Compared with control group, NAA of tumor decreased in certain degree (P<0.05). NAA in extra encephalic tumors was lower than that of intra encephalic tumors. NAA/Cr and NAA/Cho of meningiomas were lower than that of Ⅲ ostrocytoma (P<0.05). NAA could be hardly detected in cysts or necrotic region of the tumor. Signal of Cho of the solid glioma was increased (P<0.005). Cho/Cr of glioblastoma was higher than that of Ⅰ～Ⅱ ostrocytoma (P<0.05). Cho of 4 recurred tumors was obviously elevated. Lac peak was seen in about 21.5% tumors, including necrotic area of high grade gliomas and postoperative residual cavities (n=8), epidermoid (n=1), cystic degeneration of neurinoma (n=2), and tumorous edematous area (n=3). Lip signal appeared in about 21% untreated gliomas, while some Lip signal was also seen in metastases ((n=9) and extra encephalic tumors (n=11). Normal or decreased Cr was seen in each half of tumors. Lower or absent Cr was found in meningiomas. Of 9 meningiomas, 2 showed Ala.Conclusion 1HMRS is a powerful method for the study of composition and energetic metabolism of brain tumor, and is very helpful for the diagnosis and differentiation of brain tumor with the information about histologic grading, postoperative recurring and therapeutic evaluation.