ADC值鉴别诊断脑实质室管膜瘤与胶质母细胞瘤

Apparent diffusion coefficient value in differential diagnosis of intracerebral ependymoma and glioblastoma

目的探讨DWI和ADC值对脑实质室管膜瘤和胶质母细胞瘤的诊断及鉴别诊断价值。方法收集经术后病理证实的27例脑实质室管膜瘤和34例胶质母细胞瘤患者的影像学资料。对患者行常规MR平扫、增强扫描及DWI检查,并测量肿瘤实质的平均ADC值,并进行统计学分析,采用ROC曲线评价ADC值的诊断价值。结果 15例脑实质室管膜瘤DWI呈高信号,ADC值为(0.90±0.14)×10-3 mm2/s,32例胶质母细胞瘤DWI呈明显高信号,ADC值为(0.72±0.07)×10-3 mm2/s,低于室管膜瘤,差异有统计学意义(t=6.75,P<0.001)。以ADC值0.79×10-3 mm2/s为阈值诊断脑实质室管膜瘤与胶质母细胞瘤,敏感度为85.2%,特异度为97.1%,准确率为91.8%。结论 DWI及ADC值在脑实质室管膜瘤和胶质母细胞瘤的诊断及鉴别诊断中具有重要参考价值,可提高其诊断正确率。

Objective To explore the value of DWI and ADC value in differential diagnosis of intracerebral ependymoma and glioblastoma.Methods Imaging data of 27 cases of intracerebral ependymoma and 34 cases of glioblastoma pathologically confirmed were collected.All patients underwent conventional MR scan,enhanced scan and diffusion weighted MR scan.ADC maps were reconstructed,and the ADC value was measured and compared in the solid part of tumors.The ROC curves were used to evaluate the diagnostic value of ADC values.Results Fifteen cases of intracerebral ependymoma showed high signal on DWI,and the ADC value was（0.90±0.14）×10-3 mm2/s.In 34 lesions of glioblastoma,obviously hyperintensity was observed in 32 patients on DWI,and the ADC value was（0.72±0.07）×10-3 mm2/s,which was significantly lower than that of intracerebral ependymoma（t=6.75,P〈0.001）.When optimal cut point of ADC was 0.79×10-3 mm2/s for diagnosis of intracerebral ependymoma and glioblastoma,the sensitivity,specificity and accuracy was85.2%,97.1% and 91.8%.Conclusion DWI and ADC values can be applied as a complementary tool in the preoperative diagnosis and differential diagnosis of intracerebral ependymoma and glioblastoma,which can increase the diagnostic accuracy.