磁共振灌注加权成像与扩散张量成像在脑胶质瘤分级诊断中的应用

Magnetic resonance diffusion tensor and perfusion-weighted imaging for grading of cerebral gliomas

目的探讨磁共振灌注加权成像(PWI)与扩散张量成像(DTI)在脑胶质瘤分级诊断中的应用价值。方法选择在湖州市中心医院治疗的脑胶质瘤患者78例,其中低级别35例,高级别43例。测量平均扩散系数(ADC)、各向异性分数(FA)、相对平均扩散系数(rADC)、相对各向异性分数(rFA)、局部脑血流量(rCBF)、局部脑血容量(rCBV)、相对局部脑血流量(rrCBF)、相对局部脑血容量(rrCBV)值,应用SPSS软件对肿瘤不同部位以及高低级别胶质瘤间各个指标进行差异性比较,并根据受试者操作特征(ROC)曲线确定诊断阈值和分析其敏感度及特异性。结果 77例脑胶质瘤瘤体的ADC、rCBF、rCBV值分别大于相应瘤周、大于相应对侧白质的测量值;瘤体FA值小于瘤周以及对侧白质。差异均有统计学意义(P<0.05);高级别胶质瘤瘤体及瘤周的rrCBV、rrCBF分别大于低级别胶质瘤(P<0.05),高级别胶质瘤瘤体的rADC值小于低级别胶质瘤(P<0.05);ROC曲线得出rrCBF和rrCBV的曲线下面积分别为95.4%以及90.2%,相应的分级诊断的敏感度和特异度分别为87.0%、95.2%与85.3%、89.2%。结论磁共振灌注加权成像与扩散张量成像可以用于胶质瘤术前分级诊断,其中,rrCBF是诊断价值最大的指标。

Objective To study the application of magnetic resonance（ MR） perfusion-weighted imaging（ PWI） and diffusion tensor imaging（ DTI） in grading of gliomas. Methods MRI diffusion tensor imaging（ DTI） and perfusion weighted imaging（ PWI） were performed in 78 cases of cerebral gliomas（ 35 low-grade and 43 high-grade ghomas） in our hospital.The average apparent diffusion coefficient（ ADC）,fractional anisotropy（ FA）,relative ADC（ rADC）,relative FA（ rFA）,relative cerebral blood flow（ rCBF）,relative cerebra blood volume（ rCBV）,relative regional cerebral blood flow（ rrCBF）,relative regional cerebra blood volume（ rrCBV） of peritumoral regions and analogous locations in the contralateral white matter（ WM） corresponding to the tumor were measured on corresponding parameter maps generated from DTI or PWI.SPSS was used in comparative study on differentiation among different area and different grading of gliomas. Receiver operating characteristic（ ROC） analyses was also conducted to explore optimum thresholds for tumor grading. The sensitivity and specificity were also discussed. Results ADC,rCBF and rCBV values of tumor were greater than those of the peritumoral regions tissues and contralateral white matter; FA of tumors was less than that of the peritumoral regions tissues and contralateral white matter,the differences had statistical significance（ P〈0. 05）; rrCBV and rrCBF in the high-grade glioma tumors and peficancerous tissues were higher than those in the low-grade glioma,respectively（ P〈0. 05）,however,rADC value was lower than that in the low-grade glioma（ P〈0. 05）; According to the ROC curve analysis,rrCBF and rrCBV area under the curve were 95. 4% and 90. 2%,the sensitivity and specificity for tumor grading were 87. 0%,95. 2% and 85. 3%,89. 2%,respectively. Conclusion Magnetic resonance PWI and DTI can be used for preoperative grading of glioma,and rrCBF is one of the important indicators for the diagnosis of cerebral gliomas.