MR弥散加权成像对胶质瘤分级诊断中的应用价值  

The Applicative Value of MR Diffusion Weighted Imaging in the Grading of Cerebral Gliomas

作　　者：苏岩[1] 王颖[2] 张雪峰[2] 

机构地区：[1]内蒙古医学院附属医院超声诊断科,内蒙古呼和浩特010050 [2]内蒙古自治区医院影像中心MRI室,内蒙古呼和浩特010017

出　　处：《内蒙古医学杂志》2010年第3期278-282,F0004,共6页Inner Mongolia Medical Journal

摘　　要：目的：探讨MR弥散加权成像在评估脑胶质瘤分级诊断中的临床应用价值,以及在鉴别肿瘤实质部分、瘤周水肿及正常脑组织中的作用。方法：研究对象为内蒙古医院及内蒙古医学院附属医院2006年3月-2009年10月经手术病理证实42例脑胶质瘤。检查使用的磁共振装置为GE Signa 1.5T MR超导型磁共振成像仪,采用头颅正交线圈。扫描的平面2-3个,包括轴位、矢状位、冠状位T1WI和（或）T2WI。弥散加权成像采用SE平面回波成像（SE-EPI）序列,在读出、相位编码和层面选择三个方向上施加弥散梯度,取两个b值（b=0 s/mm^2,b=1000 s/mm^2）。轴位扫描,成像时间为40 s。采用随机分析软件包Functool 2进行图像资料分析,其通过b值条件不同的2帧图像点对点的计算得到每一像素的ADC值。结合常规MRI图像,在ADC图上分别测量肿瘤实质部分、瘤周水肿区、正常白质区的ADC值,并计算rADC值。分析肿瘤实质部分、瘤周水肿区及瘤周T2 WI正常表现白质区的弥散测量值（ADC值和rADC值）与肿瘤分级的关系。应用SPSS13.0软件进行统计分析。各测量区和2组不同病理学级别的肿瘤之间的弥散测量值用多样本比较方差分析方法。低级胶质瘤与高级胶质瘤的弥散测量值间的差异应用两样本比较t检验。P〈0.05为差异有统计学意义。结果：本组42例脑胶质瘤均为手术病理证实,其中低级胶质瘤（Ⅰ-Ⅱ级）17例,间变胶质瘤（Ⅲ级）16例,胶质母细胞瘤（Ⅳ级）9例。DWI对肿瘤的各部分能较好的显示。①低（Ⅰ-Ⅱ）级脑胶质瘤实质部分的ADC值和rADC值明显高于高（Ⅲ-Ⅳ）级的胶质瘤ADC值和rADC值,两者之间差异有统计学意义（P〈0.05）。②高（Ⅲ-Ⅳ）级胶质瘤周围水肿区的ADC值和rADC值明显低于低（Ⅰ-Ⅱ）级胶质瘤ADC值和rADC值（P〈0.05）。③肿瘤实质部分与瘤周水肿之间的ADC值和rADC值差异有统计学意义（P〈0.05�Objective：To investigate the clinical value of DWI in the Grading of cerebral gliomas and in differentiating tumor,edema,and normal brain tissue.Methods： The study object is the 42 patients who were diagnosed as cerebral astrocytic tumors between March 2006 and February 2008 in our hospital.All patients were examined with a 1.5-T MR unit（Signa;GE Medical Systems） by using a circularly polarized head coils.The routine MR imaging included the axial T2-weighted fast spin-echo,axial T1-weighted spin-echo and sagittal T1-weighted spin-echo sequences before contrast enhancement.Diffusion weighted imagings were performed in the transverse plane by using a spin-echo echo-planar imaging sequence,diffusion gradient encoding in three orthogonal directions applied in the x,y,and z directions;b=0 sec/mm^2 and b=1,000 sec/mm^2.Apparent Diffusion Coefficient（ADC） maps were generated with software（Functool2;GE Medical Systems）.Combined with conventional MR imaging,the ROIs,which had been used to measure the ADC values,were placed in the tumoral core,peritumoral edematous region,normal white matter.Relative ADC（rADC） were calculated too.The relationship between tumor grade and the diffusion-measurement-value of tumoral core,peritumoral edema and normal-appearing white matter were analyzed.SPSS for 13.0 statistical software package was used to assess the dfference of difference regions.The two-sample t test was used for statistical analysis.A P value of less than 0.05 was considered to represent a statistically significant difference in all cases.Results： This group of 42 cerebral gliomas were verified byhistology,incuding 17 low-grade gliomas（Ⅰ～Ⅱ）,16 astrocytoma（gradeⅢ）,9 glioblastoma multiforme（gradeⅣ）.① The ADC and rADC of low-grade gliomas were respectively higher than those high-grade ones,Significant difference was alao found between low-grade tumors and high grade tumors（P〈0.05）.② The ADC and rADC in peripheral edema regions of high-grade gliomas were significantly low-e

关 键 词：胶质瘤 磁共振成像 弥散加权成像 

分 类 号：R730.264[医药卫生—肿瘤]