体素内不相干运动扩散加权成像在脑胶质瘤术前分级诊断中的应用研究

The application study of intravoxel incoherent motion diffusion weighted imaging in the grading diagnosis of glioma before surgery

目的探讨磁共振体素内不相干运动扩散加权成像(Intravoxel Incoherent Motion Diffusion Weighted Imaging,IVIM DWI)在脑胶质瘤术前分级诊断中的应用价值。方法回顾性分析28例经病理证实为胶质瘤(低级别11例,高级别17例)并且术前行磁共振(Magnetic Resonance Imaging,MRI)常规平扫及IVIM DWI序列扫描患者的图像。IVIM DWI原始数据经工作站软件处理后得到纯水分子扩散系数D、伪扩散系数D*和灌注分数f的伪彩图,选取合适的ROI,分别测量肿瘤实质区及正常脑白质区的各参数值,采用t检验进行统计学分析。结果肿瘤实性区域的D、D*和f值较正常脑白质区增高,差异具有统计学意义(P<0.05)。高级别胶质瘤的D值低于低级别胶质瘤,f值高于低级别胶质瘤,差异均具有统计学意义(P<0.05)。高级别胶质瘤的D*值略高于低级别胶质瘤,差异无统计学意义(P>0.05)。结论通过IVIM DWI技术得到的定量参数值D、D*和f可以将肿瘤扩散和灌注信息分开,对胶质瘤患者实现更准确的术前分级诊断。

Objective To evaluate the application value of intravoxel incoherent motion diffusion weighted imaging（IVIM DWI）for the grading diagnosis of glioma before surgery.Methods Retrospectively analyzing the conventional MRI and IVIM DWI images of 28 patients with histologically proven glioma（11cases of low-grade and 17 cases of highgrade）.Regions of interest were manually set on the tumor as well as the normal brain parenchyma.The primitive IVIM DWI data were processed by the software of workstation to produce the diffusion constant（D）map,the psudodiffusion coefficient（D＊）map and the perfusion fraction（f）map.The t tests were used to evaluate the differences of measured values.Results The differences of the D,D＊ and f values between tumors and the normal brain parenchyma were statistically significant（P〈0.05）.The differences of the D and f values between the low-grade gliomas and the high-grade gliomas were statistically significant（P〈0.05）,but there was no statistical significance for the D＊ value between the low-grade gliomas and the high-grade gliomas（P〉0.05）.Conclusion Using the IVIM DWI technique to measure the D,D＊ and f values of gliomas can quantify the perfusion and more accurate diffusion information of gliomas without the contrast injection,which might play an important role in the grading diagnosis of gliomas before surgery.