表观弥散系数直方图对桥小脑角区实性神经鞘瘤与脑膜瘤的鉴别诊断价值

目的探讨表观弥散系数(apparent diffusion coefficient,ADC)直方图分析对桥小脑角区实性前庭神经鞘瘤和脑膜瘤的鉴别诊断价值。方法回顾性分析经病理证实的桥小脑角区实性前庭神经鞘瘤(14例)和脑膜瘤(29例)的弥散加权图像(diffusion weighted imag,DWI)。逐层勾画肿瘤整体感兴趣区(region of interest,ROI)获得ADC直方图分析相关参数,包括ADC第10百分位数(ADC10)、ADC平均值(ADCmean)、ADC第90百分位数(ADC90)、峰度值和偏度值。采用t检验分析各定量参数在实性前庭神经鞘瘤和脑膜瘤组之间的差异。采用受试者工作特性(receiver operatingcharacteristic,ROC)曲线分析有意义的直方图分析相关参数在两者鉴别诊断中的价值。结果实性前庭神经鞘瘤ADC10、ADCmean和ADC90值高于脑膜瘤,但两组间峰度和偏度值差异无统计学意义。以ADC90=1.126×10-3mm2/s作为诊断阈值,可获得更优的诊断价值(曲线下面积,0.975;敏感性,100%;特异性,89.66%)。结论直方图分析可进一步提高ADC对桥小脑角区实性前庭神经鞘瘤和脑膜瘤的鉴别诊断价值。

The Value of Histogram of Apparent Diffusion Coefficient in the Differential Diagnosis of Cerebellopontine Angle Solid Schwannoma and Meningioma

Objective To evaluate the value of histogram analysis of apparent diffusion coefficient(ADC) maps in differentiating solid vestibular schwannoma(VS) from meningioma in cerebellopontine angle(CPA) area. Methods Diffusion weighted(DW) images of pathologically confirmed 29 CPA meningioma(CPAM) and 14 solid VS were retrospectively analyzed. Whole-tumor regions of interest(ROIs) were drawn on all slices of the ADC maps to obtain histogram parameters, including the mean ADC(ADCmean), 10 th and 90 th percentile ADC(ADC10 and ADC90), kurtosis and skewness. Differences of ADC histogram parameters between two groups were compared using unpaired t test. Receiver operating characteristic(ROC) curves analysis were used to assess the diagnostic value of significant parameters. Results Solid VS showed significant higher ADC10, ADCmean and ADC90 than CPAM(All Ps<0.001), while no significant difference was found on kurtosis and skewness between two groups. ROC curve analysis showed, if setting ADC90=1.126×10-3mm2/s as the threshold value, optimal diagnostic value could be obtained for differentiating CPAM from VS(AUC, 0.975;Sensitivity, 100%;Specificity, 89.66%). Conclusion Histogram analysis can further improve the value of ADC for differentiating CPAM and solid VS.