ADC联合DWI鉴别诊断中枢神经细胞瘤与室管膜瘤的应用价值

The diagnostic value of ADC combined with DWI in the differentiation of the central neurocytoma and ependymoma

目的对比分析侧脑室内中枢神经细胞瘤与室管膜瘤的影像学差异,并探讨磁共振成像表观扩散系数(apparent diffusion coefficient,ADC)值联合扩散加权成像(diffusion weighted imaging,DWI)对两者的诊断及鉴别诊断价值。材料与方法收集经手术病理证实的11例侧脑室内中枢神经细胞瘤与17例侧脑室内室管膜瘤患者的术前MR平扫、增强扫描以及DWI检查的影像学资料,对其MRI征象进行对比分析,并测量两组肿瘤实质的平均ADC值,计量资料组间比较采用成组设计Mann-Whitney检验,运用受试者工作特征曲线(receiver operating characteristic curve,ROC曲线),评价ADC值的鉴别诊断价值。结果 11例侧脑室内中枢神经细胞瘤在DWI上均呈等或稍高信号,ADC均值为(0.65±0.12)×10^(-3) mm^2/s,17例侧脑室内室管膜瘤在DWI上12例呈高或稍高信号,5例呈低信号,ADC均值为(1.21±0.24)×10^(-3) mm^2/s,高于中枢神经细胞瘤,两组肿瘤实质ADC值比较差异有统计学意义(P<0.001)。以ADC值0.87×10^(-3) mm^2/s为阈值诊断中枢神经细胞瘤与室管膜瘤,ROC曲线下面积为0.98±0.01,95%可信区间为0.95~1.00,敏感度为90%,特异度为100%,准确率为90%。结论侧脑室内中枢神经细胞瘤与室管膜瘤影像表现存在一定差异,DWI及ADC值在两者的诊断及鉴别诊断中具有重要参考价值,可提高其诊断准确率。

Objective： To compare and analyze imaging features of lateral ventricular central neurocytoma （CNC） and ependymoma, exploring the value of DWI and ADC value in differential diagnosis of them. Materials and Methods： The clinical and imaging data of I 1 cases of lateral ventricular CNC and 17 cases of lateral ventricular ependymoma pathologically confirmed were collected. All patients underwent conventional MRI scan, enhanced scan and diffusion weighted MRI scan. The results were analyzed in all cases. Results： Eleven cases of lateral ventrieular CNC showed equal or slightly higher signal on DWI, and the ADC mean was （0.65±0.12）× 10-3 mm2/s. In 12 from 17 cases of lateral ventricular ependymoma, DWI showed higher or slightly higher signal, 5 cases showed low signal, ADC mean was （1.21±0.24）×10-3 mm2/s, Which was significantly higher than that of CNC （P 〈0.001）. When optimal cut point of ADC was 0.87×10-3mm2/s for diagnosis of CNC and ependymoma, the area under the ROC curve was 0.98±0.01, 95% confidence intervals was 0.95-1.00, the sensitivity, specificity and accuracy was 90%, 100% and 90%. Conclusion： The imaging features are helpful in differential diagnosis of lateral ventricular CNC and ependymoma, DWI and ADC values can be applied as a complementary tool in the preoperative diagnosis and differential diagnosis of them, which can increase the diagnostic accuracy.