质子磁共振波谱在脑肿瘤中的应用研究

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检查并经病理追踪证实的65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20例。观察定点分辨选择波谱（PRESS）采集N－乙酰天门冬氨酸（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＜0．05）；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＜0．05）；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＜0．005）；成胶质细胞瘤Cho/Cr比Ⅰ－Ⅱ级星形细胞瘤高（P＜0．05）；4例肿瘤复发Cho明显升高。约21．5％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21％的未经治疗的胶质瘤出现Lip信号；转移瘤9例，脑外肿瘤11例有不同程度的Lip显示。胶质瘤Cr正常和明显减少各半，脑膜瘤Cr低或缺乏。Ala在9例脑膜瘤中有2例显示。结论 ^1HNMRS是研究脑肿瘤物质和能量代谢的有效方法，有助于脑肿瘤的诊断和鉴别诊断，能提供其组织学分级、术后复发、疗效评价等信息。

The Clinical Application of ~1HMRS in Brain Tumor

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 T2 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.