DWI对脑实质间变性室管膜瘤与多形性胶质母细胞瘤的鉴别价值

目的对比分析脑实质间变性室管膜瘤(anaplastic ependymoma)与多形性胶质母细胞瘤(glioblastoma multiforme,GBM)MRI影像征象的差异,并探究扩散加权成像(diffusion weighted imaging,DWI)联合表观扩散系数(apparent diffusion coefficient,ADC)值对两者的鉴别诊断价值。材料与方法搜集经手术病理证实的18例脑实质间变性室管膜瘤与25例多形性胶质母细胞瘤患者的术前MR平扫、增强扫描以及DWI检查的影像学资料,对其MRI影像征象进行对比分析,并测量两组肿瘤实质的平均ADC值行Mann-Whitney U秩和检验,运用受试者工作特征曲线(receiver operating characteristic,ROC)曲线评价ADC值的鉴别诊断价值。结果 25例多形性胶质母细胞瘤在DWI上19例呈高或稍高信号,6例呈等低信号,ADC均值为(0.83±0.06)×10~(-3) mm~2/s;18例间变性室管膜瘤在DWI上14例呈高或稍高信号,4例呈等低信号,ADC均值为(1.15±0.12)×10~(-3) mm~2/s,高于前者,差异具有统计学意义(t=9.43,P0.001)。以ADC值0.96×10~(-3) mm~2/s作为两者的诊断阈值时,ROC曲线下的面积等于0.92±0.04,95%可信区间为0.84~1.00,灵敏度90%,特异度95%,准确度率90%。结论脑实质间变性室管膜瘤与多形性胶质母细胞瘤的MRI征象存在一定差异,ADC值在两者的鉴别诊断中具有重要的参考价值,可提高诊断准确率。

Diagnostic value of DWI on brain anaplastic ependymoma with glioblastoma multiforme

Objective: To compare imaging features of the brain anaplastic ependymoma and glioblastoma multiforme (GBM), exploring the value of diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) value in differential diagnosis of them. Materials and Methods: Collect the essence of 18 cases with brain surgery and pathology room brain anaplastic ependymoma and 25 cases of GBM patients with preoperative MR scan, enhanced scan and DWI imaging examination data, analyzed the MRI images, and measure the two groups of tumor of the average ADC value for Mann-Whitney U rank test, using receiver operating characteristic (ROC) curve to evaluate the differential diagnostic value of ADC value. Results: Twenty-five cases of GBM DWI in 19 cases showed high or slightly high signal, 6 cases showed low signal, the mean value of ADC was (0.83±0.06)×10-3 mm2/s.Eighteen cases of brain anaplastic ependymomain 14 cases of DWI showed high or slightly high signal, 4 cases showed low signal, the average ADC (1.15±0.12)× 10-3 mm2/s. The difference was statistically significant higher than that of GBM (t=9.43,P<0.001). With the ADC value of 0.96×10-3 mm2/s as the diagnostic threshold, the area under the ROC curve is equal to 0.92±0.04, the 95% confidence interval is 0.84 to 1, sensitivity is 90%, specificity is 95%, accuracy is 90%. Conclusions: There are some differences between the MRI signs of brain anaplastic ependymoma and GBM,ADC value has important reference value in the differential diagnosis, can improve the diagnostic accuracy.