中文摘要：

目的探讨磁共振弥散张量成像（diffusion tensor imaging,DTI）和氢质子磁共振波谱（magnetic resonance spectroscopy,1H-MRS）对胶质瘤瘤周水肿区肿瘤细胞浸润的临床评估价值。方法选取经病理证实的20例脑胶质瘤患者（其中低级别胶质瘤12例,高级别胶质瘤8例）,另选9例脑转移瘤、6例脑膜瘤作为瘤周水肿区对照组,均行常规MRI平扫＋增强、1H-MRS、DTI检查。依距强化肿瘤实质边界距离将瘤周水肿区划分为3种类型：近瘤周水肿、中瘤周水肿和远瘤周水肿。分别测定肿瘤实质、不同区域瘤周水肿和相应位置对侧正常脑组织的Cho/Cr、NAA/Cr代谢比率和平均表观弥散值（apparent diffusion coefficient,ADC）、各向异性分数值（fractional anisotropy,FA）。结果高级别胶质瘤近瘤周水肿区Cho/Cr比值为（2.79±1.03）,与肿瘤实质差异无统计学意义（t=1.674,P〉0.05）,而与对侧正常脑实质间存在明显差异（t=2.519,P〈0.05）,且明显高于低级别胶质瘤、转移瘤和脑膜瘤（P〈0.05）;高级别胶质瘤近瘤周水肿区ADC值为（1 167.70±125.69）×10-6mm2/s,与中瘤周水肿存在明显差异（t=1.744,P〈0.01）,且明显低于低级别胶质瘤、转移瘤和脑膜瘤（P〈0.01）;高级别胶质瘤近瘤周水肿区Cho/Cr比值与ADC值呈负相关（r=-0.866,P〈0.01）,而转移瘤二者之间无相关性（r=-0.177,P〉0.05）。结论根据Cho/Cr、ADC值,可以推测高级别胶质瘤近瘤周水肿区可能存在肿瘤细胞浸润。1H-MRS和DTI可为评估胶质瘤瘤周水肿区肿瘤细胞浸润提供更多的信息。

英文摘要：

Objective To prospectively investigate glioma invasion in peritumoral edema using proton magnetic resonance spectroscopy（1H-MRS）and diffusion tensor imaging（DTI）.Methods Twenty patients with histologically verified brain gliomas（12 cases of low-grade and 8 cases of high-grade）underwent routine head magnetic resonance imaging（MRI）,DTI and 1H-MRS,and so did 9 patients with metastatic brain carcinoma and 6 with meningioma as control groups in comparison of peritumoral edema among those groups.According to the distance from the tumor margin,the peritumoral edema regions were classified into three types：the proximal edema,intermediated edema and distal peritumoral edema.The ratio of choline to creatine（Cho/Cr）and N-acetyl-aspartate to creatine（NAA/Cr）,the apparent diffusion coefficient（ADC）and the fractional anisotropy（FA）value of parenchyma,different types of peritumoral edema regions and contralateral normal brain tissue were measured respectively in those four groups.Results The Cho/Cr ratio and ADC value in proximal peritumoral edema of high-grade gliomas were（2.79±1.03） and（1 167.70±125.69）×10-6 mm2/s,respectively.In proximal peritumoral edema of high-grade gliomas,the Cho/Cr ratio showed no difference from tumor parenchyma（t=1.674,P0.05）,but there was significant difference from contralateral parenchyma（t=2.519,P0.05）,and this value was obviously higher than low-grade glioma,metastatic brain carcinoma and mingioma（P0.05）.The ADC in proximal peritumoral edema of high-grade gliomas showed significant difference from intermediated peritumoral edema region（t=1.744,P0.01）and obviously lower than low-grade glioma,metastatic brain carcinoma and mingioma（P0.01）.There were a significantly negative correlation between Cho/Cr and ADC value（r=-0.866,P0.01）in proximal peritumoral edema region of high-grade gliomas,however,no significant correlation was found in peritumoral edema region of metastatic carcinoma（r=-0.177,P0.05）.Conclusion According to Cho/